cpu/intel/car: Prepare for some POSTCAR_STAGE support

The file cache_as_ram_ht.inc is used across a variety
of CPUs and northbridges. We need to split it anyway
for future C_ENVIRONMENT_BOOTBLOCK and verstage work.

Split and rename the files, remove code that is globally
implemented in POSTCAR_STAGE framework already.

Change-Id: I2ba67772328fce3d5d1ae34c36aea8dcdcc56b87
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/26747
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
8 files changed