mfd: wm831x: Use PM ops for shutdown

This helps move us towards removing the bus custom operations.

Acked-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
diff --git a/drivers/mfd/wm831x-i2c.c b/drivers/mfd/wm831x-i2c.c
index 2b29cae..a4cbefe 100644
--- a/drivers/mfd/wm831x-i2c.c
+++ b/drivers/mfd/wm831x-i2c.c
@@ -64,11 +64,13 @@
 	return wm831x_device_suspend(wm831x);
 }
 
-static void wm831x_i2c_shutdown(struct i2c_client *i2c)
+static int wm831x_i2c_poweroff(struct device *dev)
 {
-	struct wm831x *wm831x = i2c_get_clientdata(i2c);
+	struct wm831x *wm831x = dev_get_drvdata(dev);
 
 	wm831x_device_shutdown(wm831x);
+
+	return 0;
 }
 
 static const struct i2c_device_id wm831x_i2c_id[] = {
@@ -85,6 +87,7 @@
 
 static const struct dev_pm_ops wm831x_pm_ops = {
 	.suspend = wm831x_i2c_suspend,
+	.poweroff = wm831x_i2c_poweroff,
 };
 
 static struct i2c_driver wm831x_i2c_driver = {
@@ -95,7 +98,6 @@
 	},
 	.probe = wm831x_i2c_probe,
 	.remove = wm831x_i2c_remove,
-	.shutdown = wm831x_i2c_shutdown,
 	.id_table = wm831x_i2c_id,
 };