Input: mcs_touchkey - add shutdown handler

The MCS50XX series has a HW bug that requires explicit chip power down.
If chip is not powered down before shutting the system down the control
pins (powerup, interrupt) are pulled up and residue current continues
flowing into the chips making them continue consuming power.
Signed-off-by: NHeungjun Kim <riverful.kim@samsung.com>
Signed-off-by: NKyungmin Park <kyungmin.park@samsung.com>
Signed-off-by: NDmitry Torokhov <dtor@mail.ru>

drivers/input/keyboard/mcs_touchkey.c

@@ -212,6 +212,14 @@ static int __devexit mcs_touchkey_remove(struct i2c_client *client)
 	return 0;
 }
 
+static void mcs_touchkey_shutdown(struct i2c_client *client)
+{
+	struct mcs_touchkey_data *data = i2c_get_clientdata(client);
+
+	if (data->poweron)
+		data->poweron(false);
+}
+
 #ifdef CONFIG_PM_SLEEP
 static int mcs_touchkey_suspend(struct device *dev)
 {
@@ -262,6 +270,7 @@ static struct i2c_driver mcs_touchkey_driver = {
 	},
 	.probe		= mcs_touchkey_probe,
 	.remove		= __devexit_p(mcs_touchkey_remove),
+	.shutdown       = mcs_touchkey_shutdown,
 	.id_table	= mcs_touchkey_id,
 };