omapdss: extend pm notifier to handle hibernation

Add handling of missed events in omap_dss_pm_notif which are
needed to support hibernation (suspend to disk).

Signed-off-by: Grygorii Strashko <Grygorii.Strashko@linaro.org>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>