sched: Improve the scheduler

This change is for general scheduler improvement.

Change-Id: I6cb5de5a2da4bac8651a35ab9e162f290f07a51b
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
[satyap@codeaurora.org: fix trivial merge conflicts]
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>