sched: use C-states in non-small task wakeup placement logic

Currently when a non-small task wakes up, the task placement logic
first tries to find the least loaded CPU before breaking any ties
via the power cost of running the task on those CPUs. When the power
cost is also same, however, the scheduler just selects the first CPU
it came across. Use C-states to further break ties when the power
cost is the same for multiple CPUs. The scheduler will now pick a
CPU in the shallowest C-state.

Change-Id: Ie1401b305fa02758a2f7b30cfca1afe64459fc2b
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>