audio/fasttracker2: Update to 1.65

Changes since v1.63

v1.65 - 03.03.2023
- Quick fix for volume ramp delta (could be slightly off in v1.64)

v1.64 - 03.03.2023
- Increased number of precision bits for song BPM, playback time counter and
  audio->video syncing. This is a minor change and does very little in practice
  as the previous precision was already quite good.
- Audio/video sync timestamps are reset every half an hour to prevent possible
  sync drifting after several hours of playing a song without a single song stop
  (resets timestamp) in-between.
- The HPC timers are reset every half an hour instead of every hour.
  Video (if no vsync) and the scopes use these timers.
- Small code refactor for how the song is timed/ticked. Longer song-to-WAV
  renders may have a filesize change of a few bytes, but this is actually
  more correct.

(fox)