drm/panel: panel-orisetech-otm8009a: 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 <[e-mail]>
Cc: Neil Armstrong <[e-mail]>
Cc: Jessica Zhang <[e-mail]>
Reviewed-by: Jessica Zhang <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/panel/panel-orisetech-otm8009a.c

···
 		return -ENXIO;
 	}
 
-	if (bd->props.power <= FB_BLANK_NORMAL) {
+	if (bd->props.power <= BACKLIGHT_POWER_REDUCED) {
 		/* Power on the backlight with the requested brightness
 		 * Note We can not use mipi_dsi_dcs_set_display_brightness()
 		 * as otm8009a driver support only 8-bit brightness (1 param).
···
 
 	ctx->bl_dev->props.max_brightness = OTM8009A_BACKLIGHT_MAX;
 	ctx->bl_dev->props.brightness = OTM8009A_BACKLIGHT_DEFAULT;
-	ctx->bl_dev->props.power = FB_BLANK_POWERDOWN;
+	ctx->bl_dev->props.power = BACKLIGHT_POWER_OFF;
 	ctx->bl_dev->props.type = BACKLIGHT_RAW;
 
 	drm_panel_add(&ctx->panel);