demux/packet: fix version check for SMPTE 2094-50 metadata

This enum was added in lavc 62.30.100 in https://github.com/ffmpeg/ffmpeg/commit/7faa6ee2aa01
The doc/APIchanges version listed in that commit is incorrect, it's
actually lavc 62 not lavc 60.

Fixes build failure with ffmpeg between
https://github.com/ffmpeg/ffmpeg/commit/6ba6db4f195c and https://github.com/ffmpeg/ffmpeg/commit/7faa6ee2aa01

Fixes: 76df24f40c4b ("demux/packet: add support for SMPTE 2094-50 metadata")