of_mdio / mdiobus: ensure mdio devices have fwnode correctly populated

Ensure that all mdio devices populate the struct device fwnode pointer
as well as the of_node pointer to allow drivers that wish to use
fwnode APIs to work.

Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
Reviewed-by: Rob Herring <robh@kernel.org>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/phy/mdio_bus.c

@@ -270,6 +270,7 @@ static void of_mdiobus_link_mdiodev(struct mii_bus *bus,
 
 		if (addr == mdiodev->addr) {
 			dev->of_node = child;
+			dev->fwnode = of_fwnode_handle(child);
 			return;
 		}
 	}