platform-drivers-x86: set backlight type to BACKLIGHT_PLATFORM

Some newly added drivers do not set backlight type, as a result
/sys/class/backlight/<backlight>/type shows incorrect backlight type.
Signed-off-by: Axel Lin <axel.lin@gmail.com>
Cc: Corentin Chary <corentin.chary@gmail.com>
Cc: Yin Kangkai <kangkai.yin@intel.com>
Signed-off-by: Matthew Garrett <mjg@redhat.com>

drivers/platform/x86/asus-wmi.c

@@ -1025,6 +1025,7 @@ static int asus_wmi_backlight_init(struct asus_wmi *asus)
 		return power;
 
 	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = max;
 	bd = backlight_device_register(asus->driver->name,
 				       &asus->platform_device->dev, asus,

drivers/platform/x86/intel_oaktrail.c

@@ -250,6 +250,7 @@ static int oaktrail_backlight_init(void)
 	struct backlight_properties props;
 
 	memset(&props, 0, sizeof(struct backlight_properties));
+	props.type = BACKLIGHT_PLATFORM;
 	props.max_brightness = OT_EC_BL_BRIGHTNESS_MAX;
 	bd = backlight_device_register(DRIVER_NAME,
 				       &oaktrail_device->dev, NULL,