PM / wakeup: Make events_lock a RAW_SPINLOCK

The `events_lock' is acquired during suspend while interrupts are
disabled even on RT. The lock is taken only for a very brief moment.
Make it a RAW lock which avoids "sleeping while atomic" warnings on RT.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>