hwc: Add support for secure RGB layer

1. Detect and account the number of secure RGB layers present.
2. Mark secure RGB layers for MDP comp in cache based stratergy.
3. If full MDP comp and partial MDP comp fails, Mark secure RGB
   layers for MDP composition.
4. In partial MDP comp reject load based composition, if secure
   layer is present to avoid GPU composition.
5. Disable idlefallback feature if secure RGB layer is present
   to avoid GPU composition.

Change-Id: Idb4c4f09b081ec20240a2602aa3f20332fa49ad6
diff --git a/libhwcomposer/hwc_utils.h b/libhwcomposer/hwc_utils.h
index 3648ba7..88e8ffd 100644
--- a/libhwcomposer/hwc_utils.h
+++ b/libhwcomposer/hwc_utils.h
@@ -133,6 +133,9 @@
     hwc_rect_t rRoi;  //right ROI. Unused in single DSI panels.
     //App Buffer Composition index
     int  renderBufIndexforABC;
+    // Secure RGB specific
+    int secureRGBCount;
+    int secureRGBIndices[MAX_NUM_APP_LAYERS];
 };
 
 //PTOR Comp info