HWC/Copybit :: Add swap rect feature in HAL for MDP3

We brings all swap rect level checks in HAL from surfaceflinger
for MDP3.
swap rect kicks in case of
1 Only one layer is updating.
2 No overlaypping layers.
3.Both src and dst has same value.(no scaling)
4.No video layer

Change-Id: I881958994e80b53d4969beaaf51518b727a8de78

libhwcomposer/hwc_utils.cpp

@@ -1080,6 +1080,13 @@ bool isValidRect(const hwc_rect& rect)
    return ((rect.bottom > rect.top) && (rect.right > rect.left)) ;
 }
 
+bool operator ==(const hwc_rect_t& lhs, const hwc_rect_t& rhs) {
+    if(lhs.left == rhs.left && lhs.top == rhs.top &&
+       lhs.right == rhs.right &&  lhs.bottom == rhs.bottom )
+          return true ;
+    return false;
+}
+
 /* computes the intersection of two rects */
 hwc_rect_t getIntersection(const hwc_rect_t& rect1, const hwc_rect_t& rect2)
 {