fs/dyn_sync_cntrl: dynamic sync control

The dynamic sync control interface uses new power_suspend interface

While screen is on, file sync is disabled
when screen is off, a file sync is called to flush all outstanding writes
and restore file sync operation as normal.

"Modified to use early_suspend handler instead of power_suspend"

Signed-off-by: Paul Reioux <reioux@gmail.com>
Signed-off-by: Blechd0se <alex.christ@hotmail.de>

Conflicts:
	fs/Kconfig
	fs/sync.c