Revert "ptrace: introduce signal_wake_up_state() and ptrace_signal_wake_up()"

This reverts commit 74e2438754a724990de82421e8a9ea917dd1b2f9.
sched: fix rq->lock recursion

Enabling SCHED_HRTICK currently results in rq->lock recursion and a hard
hang at bootup.  Essentially try_to_wakeup() grabs rq->lock and tries
arming a hrtimer via hrtimer_restart(), which deep down tries waking up
ksoftirqd, which leads to a recursive call to try_to_wakeup() and thus
attempt to take rq->lock recursively!!

This is fixed by having scheduler queue hrtimer via
__hrtimer_start_range_ns() which avoids waking up ksoftirqd.

Signed-off-by: Srivatsa Vaddagiri <vatsa@codeaurora.org>
Change-Id: I11a13be1d9db3a749614ccf3d4f5fb7bf6f18fa1
(cherry picked from commit 4ca1d04ea0bdc225cc7db302172f3375a63f44de)
Revert "sched: add sysctl for controlling task migrations on wake"

This reverts commit 0eeabce5917d5197c01acac2f8c8070918d2e53b.
Revert "sched: add PF_WAKE_UP_IDLE"

This reverts commit 3f4321d21cb16eec34f3653c185f05e31cbe407a.