fbdev: radeonfb: Use backlight power constants

Replace FB_BLANK_ constants with their counterparts from the
backlight subsystem. The values are identical, so there's no
change in functionality or semantics.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Helge Deller <deller@gmx.de>
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240731123502.1145082-8-tzimmermann@suse.de

drivers/video/fbdev/aty/radeon_backlight.c

@@ -179,7 +179,7 @@ void radeonfb_bl_init(struct radeonfb_info *rinfo)
 		217 * FB_BACKLIGHT_MAX / MAX_RADEON_LEVEL);
 
 	bd->props.brightness = bd->props.max_brightness;
-	bd->props.power = FB_BLANK_UNBLANK;
+	bd->props.power = BACKLIGHT_POWER_ON;
 	backlight_update_status(bd);
 
 	printk("radeonfb: Backlight initialized (%s)\n", name);