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>
diff --git a/drivers/net/ethernet/renesas/sh_eth.c b/drivers/net/ethernet/renesas/sh_eth.c
index 5970d9e..8dd41e0 100644
--- a/drivers/net/ethernet/renesas/sh_eth.c
+++ b/drivers/net/ethernet/renesas/sh_eth.c
@@ -3025,15 +3025,10 @@ static int sh_mdio_init(struct sh_eth_private *mdp,
 		 pdev->name, pdev->id);
 
 	/* register MDIO bus */
-	if (dev->of_node) {
-		ret = of_mdiobus_register(mdp->mii_bus, dev->of_node);
-	} else {
-		if (pd->phy_irq > 0)
-			mdp->mii_bus->irq[pd->phy] = pd->phy_irq;
+	if (pd->phy_irq > 0)
+		mdp->mii_bus->irq[pd->phy] = pd->phy_irq;
 
-		ret = mdiobus_register(mdp->mii_bus);
-	}
-
+	ret = of_mdiobus_register(mdp->mii_bus, dev->of_node);
 	if (ret)
 		goto out_free_bus;