ramdisk: Enable deferrable KSM timer

* Saves battery.

Signed-off-by: Zhao Wei Liew <zhaoweiliew@gmail.com>
ramdisk: Tune the frequencies down

* No performance regressions are seen while this
should prevent CPU from staying at high voltages.

Signed-off-by: Zhao Wei Liew <zhaoweiliew@gmail.com>