avcodec: add av1 VAAPI decoder

Example cmdline:
ffmpeg -hwaccel vaapi -hwaccel_device /dev/dri/renderD128 -v verbose \
-c:v av1 -i input.ivf -pix_fmt yuv420p -vsync passthrough -f md5     \
-y out.md5

Signed-off-by: Fei Wang <fei.w.wang@intel.com>

libavcodec/vaapi_decode.c

@@ -410,6 +410,11 @@ static const struct {
 #if VA_CHECK_VERSION(0, 39, 0)
     MAP(VP9,         VP9_2,           VP9Profile2 ),
 #endif
+#if VA_CHECK_VERSION(1, 8, 0)
+    MAP(AV1,         AV1_MAIN,        AV1Profile0),
+    MAP(AV1,         AV1_HIGH,        AV1Profile1),
+#endif
+
 #undef MAP
 };
 
@@ -575,6 +580,7 @@ static int vaapi_decode_make_config(AVCodecContext *avctx,
             frames->initial_pool_size += 16;
             break;
         case AV_CODEC_ID_VP9:
+        case AV_CODEC_ID_AV1:
             frames->initial_pool_size += 8;
             break;
         case AV_CODEC_ID_VP8: