avformat/isom_tags: remove ipcm from movaudio_tags

ipcm is defined by ISO/IEC 23003-5, not defined by quicktime. After
adding ISO/IEC 23003-5 support, we don't need it for ticket #9219.
Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>

libavformat/isom_tags.c

@@ -321,8 +321,6 @@ const AVCodecTag ff_codec_movaudio_tags[] = {
     { AV_CODEC_ID_PCM_S16LE,       MKTAG('s', 'o', 'w', 't') },
     { AV_CODEC_ID_PCM_S16BE,       MKTAG('l', 'p', 'c', 'm') },
     { AV_CODEC_ID_PCM_S16LE,       MKTAG('l', 'p', 'c', 'm') },
-    { AV_CODEC_ID_PCM_S16BE,       MKTAG('i', 'p', 'c', 'm') },
-    { AV_CODEC_ID_PCM_S16LE,       MKTAG('i', 'p', 'c', 'm') },
     { AV_CODEC_ID_PCM_S24BE,       MKTAG('i', 'n', '2', '4') },
     { AV_CODEC_ID_PCM_S24LE,       MKTAG('i', 'n', '2', '4') },
     { AV_CODEC_ID_PCM_S32BE,       MKTAG('i', 'n', '3', '2') },