sde: Add support for horizontal and vertical flip.

Set flip flags in the driver interface to notify driver to do
horizontal/vertical/both flips using MDP.

Change-Id: Idbbffcc835a4779da5fb497a891ba5b8d9ec66b1
diff --git a/displayengine/libs/core/hw_framebuffer.cpp b/displayengine/libs/core/hw_framebuffer.cpp
index 3a0f2d0..e7c8664 100644
--- a/displayengine/libs/core/hw_framebuffer.cpp
+++ b/displayengine/libs/core/hw_framebuffer.cpp
@@ -513,6 +513,15 @@
       if (error != kErrorNone) {
         return error;
       }
+
+      if (layer.transform.flip_vertical) {
+        mdp_layer.flags |= MDP_LAYER_FLIP_UD;
+      }
+
+      if (layer.transform.flip_horizontal) {
+        mdp_layer.flags |= MDP_LAYER_FLIP_LR;
+      }
+
       mdp_layer_count++;
     }
   }