mach-msm: dyn_hotplug: Clean up properly on exit

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>
mach-msm: dyn_hotplug: Prevent immediate online of a CPU

When a CPU goes offline we should wait at least 1 sec before online it
again.

Signed-off-by: Stratos Karafotis <stratosk@semaphore.gr>