msm: Initial implementation of ghost_hotplug driver

* Ready for testing.

Signed-off-by: Zhao Wei Liew <zhaoweiliew@gmail.com>
msm: rq_stats: Don't staticize report_load_at_max_freq()

* Used by ghost_hotplug.

Signed-off-by: Zhao Wei Liew <zhaoweiliew@gmail.com>
ramdisk: Disable mpdecision service

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