sched/fair: Don't place wakee on waker cpu if colocate enabled

If both wakee and waker are in top-app,don't place wakee on waker
cpu, because most of this case waker is not going to sleep,this
will cause waker preempted and lead high runnable time,so let
scheduler to select the best cpu in this case.

Change-Id: If6eb3c0acb202197e9dd90205c581398ac049649
Signed-off-by: Biao Long <blong@codeaurora.org>