GFX-Display: Improve interpolation for CABC

GFX-Display: Improve interpolation for CABC

BZ: 29577

This patch makes CABC use 4-point interpolation and
removes color artefacts in images.

Change-Id: Ie5d478225e2b974ce8ec55f87fcbae74b6e89220
Signed-off-by: Anand Bodas <anand.v.bodas@intel.com>
Reviewed-on: http://android.intel.com:8080/42567
Reviewed-by: Shi, Yang A <yang.a.shi@intel.com>
Reviewed-by: Xu, Randy <randy.xu@intel.com>
Tested-by: Xu, Randy <randy.xu@intel.com>
Reviewed-by: Ai, Ke <ke.ai@intel.com>
Reviewed-by: Hu, Austin <austin.hu@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>