sched: EAS: kill incorrect nohz idle cpu kick

EAS won't allow NOHZ idle balancer until CPU's over utilized.  However
nohz_kick_needed() can return true.  This causes idle CPU wake up for
nothing.

Change-Id: I6e548442e29e4f85cda695e4c7101dd591b12fe6
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>
(cherry picked from commit 3989a247e2744f437233a36a0183edf3b3dfc8f1)
[trivial cherry-pick issues]
Signed-off-by: Quentin Perret <quentin.perret@arm.com>