riff: Add support for RV40 codec in AVI

Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/riff.c

@@ -359,6 +359,7 @@ const AVCodecTag ff_codec_bmp_tags[] = {
     { AV_CODEC_ID_HQX,          MKTAG('C', 'H', 'Q', 'X') },
     { AV_CODEC_ID_TDSC,         MKTAG('T', 'D', 'S', 'C') },
     { AV_CODEC_ID_HQ_HQA,       MKTAG('C', 'U', 'V', 'C') },
+    { AV_CODEC_ID_RV40,         MKTAG('R', 'V', '4', '0') },
     { AV_CODEC_ID_NONE,         0 }
 };