mutex: Move mutex spinning code from sched/core.c back to mutex.c

Signed-off-by: Waiman Long<Waiman.Long@hp.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
mutex: Make more scalable by doing less atomic operations

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Reviewed-by: Davidlohr Bueso <davidlohr.bueso@hp.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>
mutex: Queue mutex spinners with MCS lock to reduce cacheline contention

Signed-off-by: Waiman Long <Waiman.Long@hp.com>
Acked-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Francisco Franco <franciscofranco.1990@gmail.com>