msm: lpm_levels: inform the scheduler about cpu C-states

Scheduler needs to distinguish cpus that are in different C-states.
Having information on C-states, especially the cost of exiting a
particular state will help the scheduler make better task placement
decisions.

This patch extends the msm power management driver to provide required
information to the scheduler.

Change-Id: I569d5f8b3e18b0444e5517be500e82bf27d3d22f
Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>