sched/fair: Improve no-hz idle balance kicking in misfit task scenario

When there is only 1 misfit task in this runqueue,
it is in vain to do nohz idle balance for same capacity
CPU, so prefer a CPU in the other domain which may have
higher capacity CPUs. if there is no such CPU and the
current CPU has only 1 running task, avoid no-hz idle
balance kick. When there is more than 1 tasks in this
runqueue along with misfit task, choose non current sched
domain idle cpus firstly and current sched domain cpus secondly
for nohz idle balance.

Change-Id: I752e736e282ee9265c5654df3e0c9578416edd0d
Signed-off-by: Maria Yu <aiquny@codeaurora.org>