Improve the backlight code to emulate as much as possible the power
management events, as we are unable to really power on or power off the
backlight.
Signed-off-by: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
Acked-by: Richard Purdie <rpurdie@rpsys.net>
Signed-off-by: Len Brown <len.brown@intel.com>