testyuv: added validation of P010 YUV format

Also added conversion between RGB and P010, using XRGB2101010 as a bridging format in PQ space

test/testyuv_cvt.h

@@ -17,6 +17,7 @@ typedef enum
     YUV_CONVERSION_JPEG,        /**< Full range JPEG */
     YUV_CONVERSION_BT601,       /**< BT.601 (the default) */
     YUV_CONVERSION_BT709,       /**< BT.709 */
+    YUV_CONVERSION_BT2020,      /**< BT.2020 */
     YUV_CONVERSION_AUTOMATIC    /**< BT.601 for SD content, BT.709 for HD content */
 } YUV_CONVERSION_MODE;