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/libgralloc/gralloc_priv.h b/libgralloc/gralloc_priv.h
index a97cced..03d15a7 100644
--- a/libgralloc/gralloc_priv.h
+++ b/libgralloc/gralloc_priv.h
@@ -104,6 +104,7 @@
     HAL_PIXEL_FORMAT_YCbCr_444_SP           = 0x10F,
     HAL_PIXEL_FORMAT_YCrCb_444_SP           = 0x110,
     HAL_PIXEL_FORMAT_YCrCb_422_I            = 0x111,
+    HAL_PIXEL_FORMAT_BGRX_8888              = 0x112,
     HAL_PIXEL_FORMAT_INTERLACE              = 0x180,
 
 };