Adapt implementation from skylake to prepare for removal of
HIGH_MEMORY_SAVE and moving on to RELOCATABLE_RAMSTAGE.
With this change, CBMEM region is set early-on as WRBACK
with MTRRs and romstage ram stack is moved to CBMEM.
Change-Id: Idee5072fd499aa3815b0d78f54308c273e756fd1
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/15791
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
823020d56b