Merge remote-tracking branch '318/dev/msm-3.18-sched' into msm-3.18

* 318/dev/msm-3.18-sched:
  sched: restrict sync wakee placement bias with waker's demand
  sched: add preference for waker cluster CPU in wakee task placement
  sched/core: Add protection against null-pointer dereference
  sched: allow select_prev_cpu_us to be set to values greater than 100us

Change-Id: I02831c21998a5e58e33d76e0496ea564ae4f0428
Signed-off-by: Syed Rameez Mustafa <rameezmustafa@codeaurora.org>