fs/dyn_sync_cntrl: dynamic sync control

The dynamic sync control interface uses Android kernel's unique early
suspend / lat resume 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.

Change-Id: I6af33d29e5f32becdfa1a41307b181feb81720c5
 fs/dyn_sync_cntrl: Linux 3.4 Kernel compatibility fixup

Change-Id: I5a147d03653d308f9c5fc73733897f19946b8796
Signed-off-by: faux123 <reioux@gmail.com>