hammerhead: Configure sync_freq feature

Use the (optimized) sync_freq feature to stop frequency
jumping around, causing jitter. We may now even revert
timer_rate and timer_slack to the previous conservative
values.

Change-Id: Ie479a97d00d02b7f2b9867549848f1c251fcb642
hammerhead: Add hardware tunables support: vibrator

Change-Id: If8049f87b06447e7575083043d52716881facbeb
Signed-off-by: Lorenzo M <djmesias@yahoo.es>
hammerhead: Add hardware tunables support: display

Change-Id: I4eba7024542c6fb3727272c54a1521aaa662a64e
Signed-off-by: Lorenzo M <djmesias@yahoo.es>