Don't map more than 16MiB in ROM2 decode window when the SPI ROM
size is bigger than 16MiB.
TEST: amd/birman+ still boots with bigger SPI flash sizes.
Change-Id: Ie811f6a38363f2e900611b3f3f407a94d8137c89
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/86582
Reviewed-by: Maximilian Brune <maximilian.brune@9elements.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
97bf77e52e