display: Add support orientation control on ext display

- The required orientation on External can be set using the
  properyt sys.ext_orientation.
- Values can be HAL_TRANSFORM_ROT_90, HAL_TRANSFORM_ROT_270
- According to the value set, the FB_TARGET for External will
  be rotated and positioned as per aspect ratio on Ext
- For YUV(video layer) it just calculates the position, as the
  rotation should be the source orientation
- This feature is supported only for low resolution panel.

Change-Id: I3d532ee0cb8dca3c37869537b55cd8044fd9047e
diff --git a/libhwcomposer/hwc_fbupdate.h b/libhwcomposer/hwc_fbupdate.h
index 4291a50..5cf75f7 100644
--- a/libhwcomposer/hwc_fbupdate.h
+++ b/libhwcomposer/hwc_fbupdate.h
@@ -25,6 +25,10 @@
 #define LIKELY( exp )       (__builtin_expect( (exp) != 0, true  ))
 #define UNLIKELY( exp )     (__builtin_expect( (exp) != 0, false ))
 
+namespace overlay {
+    class Rotator;
+}
+
 namespace qhwc {
 namespace ovutils = overlay::utils;
 
@@ -46,6 +50,7 @@
 protected:
     const int mDpy; // display to update
     bool mModeOn; // if prepare happened
+    overlay::Rotator *mRot;
 };
 
 //Low resolution (<= 2048) panel handler.