[omxplayer] Support hdmi framerate changes during video

First commit adds NTSC (1000/1001) frequencies as explicit entries.
This avoids the hacks omxplayer does to inform GPU when that is desired.

Then, we provide a route for a GPU callback of a framerate change to trigger a refresh rate change.
Finally we enable the option on GPU to notify on framerate changes.

The end result it you can enable "adjust display refresh to match video" to "always" and if framerate changes, or demuxer reported the wrong framerate, the HDMI mode will change.