workqueue: Remove the advanced kicking of the idle workers in rebind_workers()

The commit 6d25be57 ("sched/core, workqueues: Distangle worker
accounting from rq lock") changed the schedule callbacks for workqueue
and removed the local-wake-up functionality.

Now the wakingup of workers is done by normal fashion and workers not
yet migrated to the specific CPU in concurrency managed pool can also
be woken up by workers that already bound to the specific cpu now.

So this advanced kicking of the idle workers to migrate them to the
associated CPU is unneeded now.

Signed-off-by: Lai Jiangshan <laijs@linux.alibaba.com>
Signed-off-by: Tejun Heo <tj@kernel.org>