x86/mtrr: don't assume size of ROM cached during CAR mode

Romstage and ramstage can use 2 different values for the
amount of ROM to cache just under 4GiB in the address
space. Don't assume a cpu's romstage caching policy
for the ROM.

Change-Id: I689fdf4d1f78e9556b0bc258e05c7b9bb99c48e1
Signed-off-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-on: http://review.coreboot.org/4846
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
1 file changed