bayleybay: don't mark graphics as write-combining

This code change is trying to avoid system hang due to "no enough MTRRs"
This is based on https://chromium-review.googlesource.com/174653

BUG=chrome-os-partner:33417
BRANCH=None
TEST=compile ok, make sure MTRRs are enough for memory regions.
     Check 4GiB memory usage by cat /proc/meminfo
Change-Id: Ide8177577314fddceaf20e14615b745d888b3743
Signed-off-by: Kane Chen <kane.chen@intel.com>
Reviewed-on: https://chromium-review.googlesource.com/226511
Reviewed-by: Shawn Nematbakhsh <shawnn@chromium.org>
2 files changed