drm: drop mtrr from i915
Alan Hourihane wants to set MTRR in the DDX only as otherwise
we get problems with the shared memory chipset.
From: Alan Hourihane <alanh@fairlite.demon.co.uk>
Signed-off-by: Dave Airlie <airlied@linux.ie>
authored by Dave Airlie and committed by Dave Airlie 792d2b9a 7ccf800e