xtensa: iss/network: provide release() callback

Provide release() callback for the platform device embedded into struct
iss_net_private and registered in the iss_net_configure so that
platform_device_unregister could be called for it.
Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

arch/xtensa/platforms/iss/network.c

@@ -466,6 +466,15 @@ static const struct net_device_ops iss_netdev_ops = {
 	.ndo_set_rx_mode	= iss_net_set_multicast_list,
 };
 
+static void iss_net_pdev_release(struct device *dev)
+{
+	struct platform_device *pdev = to_platform_device(dev);
+	struct iss_net_private *lp =
+		container_of(pdev, struct iss_net_private, pdev);
+
+	free_netdev(lp->dev);
+}
+
 static int iss_net_configure(int index, char *init)
 {
 	struct net_device *dev;
@@ -516,6 +525,7 @@ static int iss_net_configure(int index, char *init)
 
 	lp->pdev.id = index;
 	lp->pdev.name = DRIVER_NAME;
+	lp->pdev.dev.release = iss_net_pdev_release;
 	platform_device_register(&lp->pdev);
 	SET_NETDEV_DEV(dev, &lp->pdev.dev);