Checkpatch script recommends to use __packed instead of __attribute__((packed)). Currently the build rule for amdfwtool does not include the required header file with __packed definition. Update the compiler flag to include the required header file. BUG=None TEST=Build amdfwtool. Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com> Change-Id: I448cbad533608dd5c2bd4f2d827fcc5db5dee5cb Reviewed-on: https://review.coreboot.org/c/coreboot/+/67384 Reviewed-by: Jon Murphy <jpmurphy@google.com> Tested-by: build bot (Jenkins) <no-reply@coreboot.org>