Saving cbmem_top across stages is not needed anymore so EBDA should
not be used. The guard to cbmem_top_chipset implementation was
inappropriate.
Change-Id: Ibbb3534b88de4f7b6fc39675a77461265605e56e
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/36614
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michael Niewöhner