fs/dyn_sync_cntrl: dynamic Fsync control v1.5 [faux123]

The dynamic Fsync 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.

updated for 8974 kernels

Signed-off-by: Paul Reioux <reioux@gmail.com>;