ACPI / PM: Add more run-time wake-up fields

Use the run_wake flag to mark all devices for which run-time wake-up
events may be generated by the platform.  Introduce a new wake-up
flag, always_enabled, for marking devices that should be permanently
enabled to generate run-time events.  Also, introduce a reference
counter for run-wake devices and a function that will initialize all
of the run-time wake-up fields for given device.

Signed-off-by: Rafael J. Wysocki <rjw@sisk.pl>
Acked-by: Len Brown <len.brown@intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>