Add support for MPEG2 quantization matrices

This adds support for MPEG2 quantization matrices, which are optional
given that fallback default matrices are used (on the kernel side) when
no such matrix is provided.

Signed-off-by: Paul Kocialkowski <paul.kocialkowski@bootlin.com>

src/surface.h

@@ -64,6 +64,8 @@ struct object_surface {
 	union {
 		struct {
 			VAPictureParameterBufferMPEG2 picture;
+			VAIQMatrixBufferMPEG2 iqmatrix;
+			bool iqmatrix_set;
 		} mpeg2;
 		struct {
 			VAIQMatrixBufferH264 matrix;