hwc: Add a new check for DMA state change

Add a check to bail out of MDP composition in cases when we need
to switch the DMA state.

Change-Id: Iab3978df77d7f0e7cee28603189292504706c463
diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index 3f903b1..330d22d 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -597,6 +597,8 @@
     mutable Locker mDrawLock;
     //Drawing round when we use GPU
     bool isPaddingRound;
+    // Used to mark composition cycle when DMA state change is required
+    bool isDMAStateChanging;
     // External Orientation
     int mExtOrientation;
     //Flags the transition of a video session