remove useless tags, codec_get_id matches independently and qt uses lower case tags

Originally committed as revision 12199 to svn://svn.ffmpeg.org/ffmpeg/trunk

libavformat/aiff.c

@@ -29,9 +29,7 @@ static const AVCodecTag codec_aiff_tags[] = {
     { CODEC_ID_PCM_S24BE, MKTAG('N','O','N','E') },
     { CODEC_ID_PCM_S32BE, MKTAG('N','O','N','E') },
     { CODEC_ID_PCM_ALAW, MKTAG('a','l','a','w') },
-    { CODEC_ID_PCM_ALAW, MKTAG('A','L','A','W') },
     { CODEC_ID_PCM_MULAW, MKTAG('u','l','a','w') },
-    { CODEC_ID_PCM_MULAW, MKTAG('U','L','A','W') },
     { CODEC_ID_MACE3, MKTAG('M','A','C','3') },
     { CODEC_ID_MACE6, MKTAG('M','A','C','6') },
     { CODEC_ID_GSM, MKTAG('G','S','M',' ') },