Added fsync on/off support.

Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>

fs: sync: enable fsync by default.

Signed-off-by: franciscofranco <franciscofranco.1990@gmail.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>

fs: sync: add missing return if fsync is disabled from userspace.

Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
acpuclock: Deactivate 864mhz
Add 81MHz low frequencie for test
Undervolt 81MHz frequencie
Correct cpuclock and set correct voltages