drivers: net: Remove device_node checks with of_mdiobus_register()

A number of drivers have the following pattern:

if (np)
	of_mdiobus_register()
else
	mdiobus_register()

which the implementation of of_mdiobus_register() now takes care of.
Remove that pattern in drivers that strictly adhere to it.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
Reviewed-by: Fugang Duan <fugang.duan@nxp.com>
Reviewed-by: Antoine Tenart <antoine.tenart@bootlin.com>
Reviewed-by: Jose Abreu <joabreu@synopsys.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/marvell/mvmdio.c

@@ -348,10 +348,7 @@ static int orion_mdio_probe(struct platform_device *pdev)
 		goto out_mdio;
 	}
 
-	if (pdev->dev.of_node)
-		ret = of_mdiobus_register(bus, pdev->dev.of_node);
-	else
-		ret = mdiobus_register(bus);
+	ret = of_mdiobus_register(bus, pdev->dev.of_node);
 	if (ret < 0) {
 		dev_err(&pdev->dev, "Cannot register MDIO bus (%d)\n", ret);
 		goto out_mdio;