Add libvpx and x264 dependency:

• the bundled ffmpeg seems to want to use it despite libvpx being disabled in the handbrake patches
• x264 comes bundled, but there are reports it's needed as a dependency so that the port builds, so better safe than sorry

This allows to build the port by hand (make install in the port directory).

The BROKEN line stays in, seems those changes don't make poudriere happy.

PR: 199126
Submitted by: w.schwarzenfeld@utanet.at
Discussed with: olgeni