Changes looks fine, although I'm bit unsure about --disable-mpg123 and iconv:wchar_t parts. Can you explain them?

By default the configure script will autodetect (lib)mpg123 (if available) which causes a dependency mismatch since it's not defined. As for functionality it's redundant because of ffmpeg and normally doesn't get pulled in. To be honest I don't know exactly what settings Philipp used but I can try to track it down however it's most likely due to a non standard option in some dependency.
Regarding iconv:wchar_t this was added in the patch Philipp submitted ( https://bugs.freebsd.org/bugzilla/attachment.cgi?id=226246 ) and grepping VLC's source code showed a few instances where it was used.