Implement unit tests for lib/b64_decode module.
Signed-off-by: Anna Karas <aka@semihalf.com>
Change-Id: Id5fe9272e30eaff3d086a95241b3819101089c2b
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42313
Reviewed-by: Paul Fagerburg <pfagerburg@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>