intel_idle: Clean up all registered devices on exit.

intel_idle: Clean up all registered devices on exit.

Orabug: 24810432

This driver registers cpuidle devices when a CPU comes online, but it
leaves the registrations in place when a CPU goes offline.  The module
exit code only unregisters the currently online CPUs, leaving the
devices for offline CPUs dangling.

This patch changes the driver to clean up all registrations on exit,
even those from CPUs that are offline.

Signed-off-by: Richard Cochran <rcochran@linutronix.de>
Signed-off-by: Len Brown <len.brown@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
(cherry picked from commit 3e66a9ab53641a0f7a440e56f7b35bf5d77494b3)
Signed-off-by: Brian Maly <brian.maly@oracle.com>