[media] tw686x: use a formula instead of two tables for div
Instead of using two tables to estimate the temporal decimation
factor, use a formula. This allows to get the closest fps, which
sounds better than the current tables.
Also, the current code doesn't store the real framerate.
This patch fixes the above issues.
[Ezequiel:
- introduce a TW686X_MAX_FPS macro for max_fps.
- use hweight_long instead of open coding the set bits count.]