drm/i915: Move gtt_mtrr to i915_gtt

for file in `ls drivers/gpu/drm/i915/*.c` ; do
	sed -i "s/mm.gtt_mtrr/gtt.mtrr/" $file;
done

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>