sched: EAS: add core isolation support

Isolated CPUs are only allowed to run pinned kernel threads, timers
and hrtimers. Don't consider isolated CPUs during energy aware task
placement for fair and RT class tasks.

Change-Id: I6c53f2ce2bcb2355f9d0d99e1ba502a91074adac
Signed-off-by: Pavankumar Kondeti <pkondeti@codeaurora.org>