For ADL DIMM_MAX is a soc property and not a mainboard property.
Change-Id: I834b631ffb9b7b2272ec631122de61136e55651a
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/84207
Reviewed-by: Alicja Michalska <ahplka19@gmail.com>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>