display: Add BufferMirrorMode support for External

- In Buffer mirror mode, the output on the external should be rotated
  based on the primary orientation.
- this is used for the side sync feature.
- buffermirrormode has higher precedence over external orientation
- Add binder interface to enable/disable buffermirror mode

Change-Id: Ibea0af9627d69b4d42453adc868b113d82613437
diff --git a/libqservice/QService.h b/libqservice/QService.h
index 8eefa21..a241d44 100644
--- a/libqservice/QService.h
+++ b/libqservice/QService.h
@@ -50,6 +50,7 @@
     virtual void connect(const android::sp<qClient::IQClient>& client);
     virtual android::status_t screenRefresh();
     virtual void setExtOrientation(uint32_t orientation);
+    virtual void setBufferMirrorMode(uint32_t enable);
     static void init();
 private:
     QService();