overlay: Add a flag for compilation with new API

 * ROI fields have changed for dual-dsi systems. Add
   an ifdef to allow compilation with old kernels.

Change-Id: Ie18404bba2c5afe4e8b913c1b4eee2a588f37acb
hwc: Consider FLIP flags for partial update.

FLIP flags need to be considered while calculating srcCrop and
displayFrame even when a layer is updated partially on dual DSI
panels.

Change-Id: I097b3335e66566d6639848bc8f8382bfeabb7f54