PM QoS: Add max online cpus as PM QoS parameter

Bug 894200

Signed-off-by: Alex Frid <afrid@nvidia.com>
Reviewed-on: http://git-master/r/71034
Reviewed-by: Rohan Somvanshi <rsomvanshi@nvidia.com>
Tested-by: Rohan Somvanshi <rsomvanshi@nvidia.com>

Change-Id: Iacad66fe09645f860d16558b8ec8e884802a1d7b