GFX-Display: Enable CABC from boot

GFX-Display: Enable CABC from boot

BZ: 29291

CABC was being enabled in power_up code which was not called
during boot, as the display was already initialized by FW.
Added code to enable CABC without power cycling display.
Changed to send bytes instead of words due to BZ 28302.

Change-Id: I3e8f529fb9b296a9c7563eb618fb192b0ffa9411
Signed-off-by: Anand Bodas <anand.v.bodas@intel.com>
Reviewed-on: http://android.intel.com:8080/40975
Reviewed-by: Ai, Ke <ke.ai@intel.com>
Reviewed-by: Hu, Austin <austin.hu@intel.com>
Reviewed-by: Tong, BoX <box.tong@intel.com>
Tested-by: Tong, BoX <box.tong@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>