checkpatch.conf: Disable gerrit change ID for coreboot

The GERRIT_CHANGE_ID Error is useful for the linux flow, but since
coreboot uses gerrit, giving an error on the ID doesn't make sense.

Change-Id: I7f6efb5559027ed9497ee85497bb4b4e786f9901
Signed-off-by: Martin Roth <[email protected]>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63030
Tested-by: build bot (Jenkins) <[email protected]>
Reviewed-by: Elyes Haouas <[email protected]>
Reviewed-by: Felix Singer <[email protected]>
Reviewed-by: Subrata Banik <[email protected]>

Author: Martin Roth

.checkpatch.conf

@@ -22,6 +22,7 @@
 --ignore PRINTK_WITHOUT_KERN_LEVEL
 --ignore ASSIGN_IN_IF
 --ignore UNNECESSARY_ELSE
+--ignore GERRIT_CHANGE_ID
 
 # FILE_PATH_CHANGES seems to not be working correctly. It will
 # choke on added / deleted files even if the MAINTAINERS file