Gfx-Display: fixed the issue that HDMI can't show video playback with HW Composer.

Gfx-Display: fixed the issue that HDMI can't show video playback with HW Composer.

BZ: 16345

When play video with HDMI by Gallery, overlay crashes because overlay plane size
(= HDMI sink device mode) exceeds DC source image size in aspect ratio mode.

Fixed the issue by setting HDMI default scaling mode to center. And Resoure Manager
can decide to set HDMI scaling to center before playing video via HDMI, to avoid
such issue.

Change-Id: I8cf42740962377125ac9ed631cd1fa828b57555f
Signed-off-by: Austin Hu <austin.hu@intel.com>
Reviewed-on: http://android.intel.com:8080/26915
Reviewed-by: Xu, Randy <randy.xu@intel.com>
Tested-by: Xu, Randy <randy.xu@intel.com>
Reviewed-by: buildbot <buildbot@intel.com>
Tested-by: buildbot <buildbot@intel.com>