Detect 'yuv2' as rawvideo also in avi.

Signed-off-by: Michael Niedermayer <michaelni@gmx.at>

libavformat/riff.c

@@ -174,6 +174,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { CODEC_ID_RAWVIDEO,     MKTAG('2', 'V', 'u', '1') },
     { CODEC_ID_RAWVIDEO,     MKTAG('2', 'v', 'u', 'y') },
     { CODEC_ID_RAWVIDEO,     MKTAG('y', 'u', 'v', 's') },
+    { CODEC_ID_RAWVIDEO,     MKTAG('y', 'u', 'v', '2') },
     { CODEC_ID_RAWVIDEO,     MKTAG('P', '4', '2', '2') },
     { CODEC_ID_RAWVIDEO,     MKTAG('Y', 'V', '1', '2') },
     { CODEC_ID_RAWVIDEO,     MKTAG('Y', 'V', '1', '6') },