Revert CGROUP_TIMER_SLACK commits ( battery drain )

Revert "shooteru: enable CGROUP_TIMER_SLACK"

This reverts commit ee640f03784d7f5c7f4a3273f98aabf9f78f46df.

Revert "sched: unthrottle rt runqueues in __disable_runtime()"

This reverts commit 91d985c4c7199d662581b8f635e1a2a44dda64e5.

Revert "wakeup: Use irqsave/irqrestore for events_lock"

This reverts commit dd899396f0201ff65453b27b940fa70726934597.

Revert "cgroups: introduce timer slack controller"

This reverts commit e860931a6e2771f263c063b8f2a88a4b6f9bc093.