hwc/copybit: Handle "R/B swap" for RGBA and RGBX color formats.

1.Framework notifies HAL with "HWC_FORMAT_RB_SWAP" layer flag to handle
a limitation where R and B components were swapped in Rendering phase.
2.Add "R/B swap" in hwc query to enable framework to query for support
in display HAL, at run-time.

Change-Id: I3b44d15b51b4f24939048fee9d1bac2b9009c97c
diff --git a/liboverlay/overlayUtils.cpp b/liboverlay/overlayUtils.cpp
index df2c09e..fd8bfe2 100644
--- a/liboverlay/overlayUtils.cpp
+++ b/liboverlay/overlayUtils.cpp
@@ -100,6 +100,8 @@
             return MDP_RGB_565;
         case HAL_PIXEL_FORMAT_BGRA_8888:
             return MDP_BGRA_8888;
+        case HAL_PIXEL_FORMAT_BGRX_8888:
+            return MDP_BGRX_8888;
         case HAL_PIXEL_FORMAT_YV12:
             return MDP_Y_CR_CB_GH2V2;
         case HAL_PIXEL_FORMAT_YCbCr_422_SP: