bivideo_update_powerstate
static void bivideo_update_powerstate(struct bivideo_softc *, int);
bivideo_update_powerstate(sc, PWRSTAT_ALL);
bivideo_update_powerstate(sc, PWRSTAT_ALL);
bivideo_update_powerstate(sc, PWRSTAT_ALL);
bivideo_update_powerstate(sc, PWRSTAT_BACKLIGHT);