leds: syscon: Use resource managed variant of device register

We have a MFD driver compiled as module instantiating this driver. When
unloading that module, those LED devices are not removed, which produces
conflicts, when that module is inserted again.

Signed-off-by: Alexander Dahl <[e-mail]>
Signed-off-by: Jacek Anaszewski <[e-mail]>

drivers/leds/leds-syscon.c

···
 	}
 	sled->cdev.brightness_set = syscon_led_set;
 
-	ret = led_classdev_register(dev, &sled->cdev);
+	ret = devm_led_classdev_register(dev, &sled->cdev);
 	if (ret < 0)
 		return ret;