Build: Enable GNU null-dereference check

Patch psa-arch-tests repo to enable GNU null-dereference check. This changes
is already part of psa-arch-tests.

Signed-off-by: Gabor Toth <gabor.toth@arm.com>
Change-Id: Ia155de7388d7f2c6f20d64d317b9d76f0decdffe
1 file changed