movenc: allow alternative hvc1 h.265 codec tag

If AVCodecParameters.codec_tag is 'hvc1' use it instead of 'hev1' for
h.265 streams. QuickTime (and other Apple software) requires 'hvc1'.

(cherry picked from commit 84ab1cc4)
Signed-off-by: Derek Buitenhuis <derek.buitenhuis@gmail.com>

libavformat/movenc.c

@@ -6437,6 +6437,7 @@ const AVCodecTag codec_mp4_tags[] = {
     { AV_CODEC_ID_MPEG4       , MKTAG('m', 'p', '4', 'v') },
     { AV_CODEC_ID_H264        , MKTAG('a', 'v', 'c', '1') },
     { AV_CODEC_ID_HEVC        , MKTAG('h', 'e', 'v', '1') },
+    { AV_CODEC_ID_HEVC        , MKTAG('h', 'v', 'c', '1') },
     { AV_CODEC_ID_MPEG2VIDEO  , MKTAG('m', 'p', '4', 'v') },
     { AV_CODEC_ID_MPEG1VIDEO  , MKTAG('m', 'p', '4', 'v') },
     { AV_CODEC_ID_MJPEG       , MKTAG('m', 'p', '4', 'v') },