sched: sched_avg: Add snapshot of sched_avg

This snapshot is taken from msm-4.14 as of commit 43980276ecf9014
("sched/sched_avg: make number of running tasks conservative").

Change-Id: Ia5f608fe1c1715489e7c0fc6e5736b80bee5bae7
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>