add new surface format fourcc XYUV

Signed-off-by: Carl Zhang <carl.zhang@intel.com>
diff --git a/va/va.h b/va/va.h
index e9c0b21..6c89173 100644
--- a/va/va.h
+++ b/va/va.h
@@ -4555,6 +4555,11 @@
  * The four planes contain: alpha, blue, green, red respectively.
  */
 #define VA_FOURCC_ABGR64        0x34474241
+/** XYUV: packed 8-bit YUVX 4:4:4.
+ *
+ * Four bytes per pixel: X, Y, U, V.
+ */
+#define VA_FOURCC_XYUV          0x56555958
 
 /* byte order */
 #define VA_LSB_FIRST		1