sched: Improve the scheduler

This change is for general scheduler improvement.

Change-Id: I22994886e3a6128e9235e3cf698b0bb405275194
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
[satyap@codeaurora.org: fix trivial merge conflict]
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>