drm/radeon: 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: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: Xinhui Pan <Xinhui.Pan@amd.com>
Acked-by: Alex Deucher <alexander.deucher@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240731122311.1143153-9-tzimmermann@suse.de

drivers/gpu/drm/radeon/atombios_encoders.c

@@ -249,7 +249,7 @@ void radeon_atom_backlight_init(struct radeon_encoder *radeon_encoder,
 	 */
 	if (bd->props.brightness == 0)
 		bd->props.brightness = RADEON_MAX_BL_LEVEL;
-	bd->props.power = FB_BLANK_UNBLANK;
+	bd->props.power = BACKLIGHT_POWER_ON;
 	backlight_update_status(bd);
 
 	DRM_INFO("radeon atom DIG backlight initialized\n");

drivers/gpu/drm/radeon/radeon_legacy_encoders.c

@@ -450,7 +450,7 @@ void radeon_legacy_backlight_init(struct radeon_encoder *radeon_encoder,
 	}
 
 	bd->props.brightness = radeon_legacy_backlight_get_brightness(bd);
-	bd->props.power = FB_BLANK_UNBLANK;
+	bd->props.power = BACKLIGHT_POWER_ON;
 	backlight_update_status(bd);
 
 	DRM_INFO("radeon legacy LVDS backlight initialized\n");