sched/fair: Add policy for restricting prefer_spread to newly idle balance

Add policy for restricting prefer_spread to newly idle load balance
by expanding the tunable range.

To allow lower capacity CPUs to do aggressive newly idle load balance:
echo 3 > /proc/sys/kernel/sched_prefer_spread

To allow bother lower capacity and higher capacity CPUs to do
aggressive newly idle load balance:
echo 4 > /proc/sys/kernel/sched_prefer_spread

Change-Id: Ia62ddb29bdf592a956a9688f277178ef71dee1b3
Signed-off-by: Satya Durga Srinivasu Prabhala <satyap@codeaurora.org>
[pkondeti@codeaurora.org: The tunable range is expanded]
Co-developed-by: Pavankumar Kondeti <pkondeti@codeaurora.org>
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>