sde: partial update implementation

  1. Partial update for non-split and split panels.
  2. Currently, partial update is enabled on qualified
     primary displays only.
Change-Id: I4d37e83e0991693cce950dc1428ed8c30d4f6caa
diff --git a/displayengine/libs/utils/rect.cpp b/displayengine/libs/utils/rect.cpp
index 9b05951..630cebb 100644
--- a/displayengine/libs/utils/rect.cpp
+++ b/displayengine/libs/utils/rect.cpp
@@ -122,11 +122,11 @@
     return LayerRect();
   }
 
-  if(!IsValid(rect1)){
+  if (!IsValid(rect1)) {
     return rect2;
   }
 
-  if(!IsValid(rect2)){
+  if (!IsValid(rect2)) {
     return rect1;
   }