mfd: rn5t618: Unregister restart handler on remove

Remove the restart handler registered in probe on device remove.

Fixes: a370f60a ("mfd: rn5t618: Register restart handler")
Signed-off-by: NStefan Agner <stefan@agner.ch>
Signed-off-by: NLee Jones <lee.jones@linaro.org>

drivers/mfd/rn5t618.c

@@ -155,6 +155,8 @@ static int rn5t618_i2c_remove(struct i2c_client *i2c)
 		pm_power_off = NULL;
 	}
 
+	unregister_restart_handler(&rn5t618_restart_handler);
+
 	return 0;
 }