Fixes for compiling with -fno-common, default in GCC 10.

Taken from upstream:
https://github.com/qca/open-ath9k-htc-firmware/commit/559e3eba3b4cf103da6b8d022f3e1387278b9db8

diff --git a/target_firmware/magpie_fw_dev/target/init/app_start.c b/target_firmware/magpie_fw_dev/target/init/app_start.c
--- a/target_firmware/magpie_fw_dev/target/init/app_start.c
+++ b/target_firmware/magpie_fw_dev/target/init/app_start.c
@@ -52,6 +52,8 @@
 #define ALLOCRAM_START       ( ((unsigned int)&_fw_image_end) + 4)
 #define ALLOCRAM_SIZE        ( SYS_RAM_SZIE - ( ALLOCRAM_START - SYS_D_RAM_REGION_0_BASE) - SYS_D_RAM_STACK_SIZE)
 
+void (* _assfail_ori)(struct register_dump_s *);
+
 // support for more than 64 bytes on command pipe
 extern void usb_reg_out_patch(void);
 extern int _HIFusb_get_max_msg_len_patch(hif_handle_t handle, int pipe);
diff --git a/target_firmware/magpie_fw_dev/target/init/init.h b/target_firmware/magpie_fw_dev/target/init/init.h
--- a/target_firmware/magpie_fw_dev/target/init/init.h
+++ b/target_firmware/magpie_fw_dev/target/init/init.h
@@ -46,7 +46,7 @@
 void AR6002_fatal_exception_handler_patch(CPU_exception_frame_t *exc_frame);
 void exception_reset(struct register_dump_s *dump);
 
-void (* _assfail_ori)(struct register_dump_s *);
+extern void (* _assfail_ori)(struct register_dump_s *);
 void HTCMsgRecvHandler_patch(adf_nbuf_t hdr_buf, adf_nbuf_t buffer, void *context);
 void HTCControlSvcProcessMsg_patch(HTC_ENDPOINT_ID EndpointID, adf_nbuf_t hdr_buf,
 				   adf_nbuf_t pBuffers, void *arg);
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<tr><td><span title='2018-02-28 18:23:31 +0100'>2018-02-28</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=8297ff0f931a677c51ca7c64a844a55cd6cd2ef4'>gnu: pcre2: Update to 10.31.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2018-01-19 23:59:20 -0500'>2018-01-19</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=e074a655dd6497daafbd62737e3b63f3d5aa7985'>Merge branch 'master' into core-updates</a></td><td>Mark H Weaver</td></tr>
<tr><td><span title='2018-01-13 21:25:40 +0100'>2018-01-13</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=265c31f5a377851eb583dfeaaaae6132e085cfac'>gnu: pcre: Use HTTPS for home pages.</a><span class='msg-avail'>...</span></td><td>Tobias Geerinckx-Rice</td></tr>
<tr><td><span title='2017-10-01 22:16:41 +0300'>2017-10-01</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=0b7f9806dbde1a7c1ded4218e499319d7eafbe7a'>gnu: pcre: Update to 8.41.</a><span class='msg-avail'>...</span></td><td>Efraim Flashner</td></tr>
<tr><td><span title='2017-07-23 03:42:12 -0400'>2017-07-23</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=6c1a317e29c45e85e3a0e050612cdefe470b100c'>Merge branch 'master' into core-updates</a></td><td>Leo Famulari</td></tr>
<tr><td><span title='2017-07-20 08:26:40 -0400'>2017-07-20</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=426b0b898f70a58133d80779980f163a5761686e'>gnu: pcre: Update replacement to 8.41 [fixes CVE-2017-{7244,7245,7246}].</a><span class='msg-avail'>...</span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2017-07-03 23:51:22 +0200'>2017-07-03</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=d5ec5ed7197d121130af6953378bcfd8929a9754'>packages: Mark 'replacement' as an "innate" field.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-05-24 12:05:47 +0200'>2017-05-24</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=d1a914082b7e53636f9801769ef96218b2125c4b'>Merge branch 'master' into core-updates</a></td><td>Ricardo Wurmus</td></tr>
<tr><td><span title='2017-05-07 17:46:00 -0400'>2017-05-07</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=af6e2385b3125924f34188d81370dd71cdbe9ddc'>gnu: pcre2: Fix build configuration for pcre2.</a><span class='msg-avail'>...</span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2017-05-07 17:46:00 -0400'>2017-05-07</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=37f46a4bc51886c0d0df797bfbb13a50fe647567'>gnu: pcre2: Fix CVE-2017-8786.</a><span class='msg-avail'>...</span></td><td>Leo Famulari</td></tr>
<tr><td><span title='2017-04-10 23:54:46 +0200'>2017-04-10</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=a97f0ee1368499dc40ea30002fcb6e06c7880acb'>gnu: pcre: Patch CVE-2017-7186.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-04-10 23:54:46 +0200'>2017-04-10</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=18d0cec29e22cdbc27c486129d1a1425de27f03f'>gnu: pcre2: Patch CVE-2017-7186.</a><span class='msg-avail'>...</span></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-03-09 16:35:41 +0100'>2017-03-09</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=e90e0fad1b3ba79d81f02424e143ee6f4f736e8b'>Merge branch 'master' into core-updates</a></td><td>Ludovic Courtès</td></tr>
<tr><td><span title='2017-03-07 23:21:22 +0100'>2017-03-07</span></td><td><a href='/guix/commit/gnu/packages/pcre.scm?id=9bb766e70d03164cb902122f3bbfbf46547f6cda'>gnu: pcre2: Update to 10.23.</a><span class='msg-avail'>...</span></td><td>Marius Bakke</td></tr>