ENGR00243337 Enable swap rectangle for surfaceflinger

swap rectangle feature can reduce composing region to improve performance,
also reduce power consumption during UI partial update, like mouse moving.

Google enabled this feature in Android 3.0 and the older versions,
but removed it now since some GPU devices have no this feature.

Add this feature back because i.mx6 GPU support swap rectangle.

Change-Id: Ifca99f44f0bde0fc1cc3228c11e3cfd635d0aacb
Signed-off-by: Xianzhong <b07117@freescale.com>