sched: EAS: avoid sync-wakup on an overutilized CPU

The sync wake-up hint should be weak but at present it precedences
cpu_overutilized() so leads excessive task packing unnecessarily.
Ignore sync-wakeup when CPU is over utilized.

Change-Id: Ia286c9a5de18fdac7482fe09da2f4f3325732389
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>