ACPI: video: improve PM notifer callback

PM notifier callbacks should check for supported events rather than filter
out the unsupported events. So that it won't break when a new event is
introduced.

No functional change in this patch.

Signed-off-by: Zhang Rui <rui.zhang@intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>