Peppy, Haswell: refactor and create set_translation_table function in haswell/gma.c

The code to set the graphics translation table has been in the
mainboards, but should be in the northbridge support code.

Move the function, give it a better name, and enable support for > 4
GiB while we're at it, in the remote possibility that we get some 8
GiB haswell boards.

Change-Id: I72b4a0a88e53435e00d9b5e945479a51bd205130
Signed-off-by: Ronald G. Minnich <rminnich@google.com>
Reviewed-on: https://chromium-review.googlesource.com/171160
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Furquan Shaikh <furquan.m.shaikh@gmail.com>
Commit-Queue: Ronald Minnich <rminnich@chromium.org>
Tested-by: Ronald Minnich <rminnich@chromium.org>
(cherry picked from commit d5a429498147c479eb51477927e146de809effce)
Signed-off-by: Isaac Christensen <isaac.christensen@se-eng.com>
Reviewed-on: http://review.coreboot.org/6741
Tested-by: build bot (Jenkins)