hwc: 8x26: Composition policy when WFD connected

When WFD is connected to 8x26
1) On Video transition, have 1 padding round if external connected.
Required to shift pipes across mixers.
2) Request DMA pipe always for FB on WFD.
Necessary for rotation + writeback
3) Disable non-worm-hole calcs on external (because of 2)
4) Disable action-safe calcs on external (because of 2)

Change-Id: I63b50b2477db443f9ea1d3fa610b59295c9359b7
diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index 54a118c..916a59d 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -316,6 +316,8 @@
     bool isPaddingRound;
     // External Orientation
     int mExtOrientation;
+    //Flags the transition of a video session
+    bool mVideoTransFlag;
 };
 
 namespace qhwc {