leds-lp55xx: add new function for removing device attribtues

 lp55xx_unregister_sysfs() is used for removing lp55xx device attributes.
 Chip specific and engine attributes are removed on unloading the driver.

Signed-off-by: Milo(Woogyom) Kim <milo.kim@ti.com>
Signed-off-by: Bryan Wu <cooloney@gmail.com>
diff --git a/drivers/leds/leds-lp55xx-common.c b/drivers/leds/leds-lp55xx-common.c
index 9638ad4..782ab84 100644
--- a/drivers/leds/leds-lp55xx-common.c
+++ b/drivers/leds/leds-lp55xx-common.c
@@ -509,6 +509,18 @@
 }
 EXPORT_SYMBOL_GPL(lp55xx_register_sysfs);
 
+void lp55xx_unregister_sysfs(struct lp55xx_chip *chip)
+{
+	struct device *dev = &chip->cl->dev;
+	struct lp55xx_device_config *cfg = chip->cfg;
+
+	if (cfg->dev_attr_group)
+		sysfs_remove_group(&dev->kobj, cfg->dev_attr_group);
+
+	sysfs_remove_group(&dev->kobj, &lp55xx_engine_attr_group);
+}
+EXPORT_SYMBOL_GPL(lp55xx_unregister_sysfs);
+
 MODULE_AUTHOR("Milo Kim <milo.kim@ti.com>");
 MODULE_DESCRIPTION("LP55xx Common Driver");
 MODULE_LICENSE("GPL");