These stub params need to be synced with the code in smm_stub.S and
are consumed by both the smmloader and smmloader_v2. So it is better
to have the definition located in one place.
Change-Id: Ide3e0cb6dea3359fa9ae660eab627499832817c9
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/50761
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>