staging: octeon: Call SET_NETDEV_DEV()

The Octeon driver calls into PHYLIB which now checks for
net_device->dev.parent, so make sure we do set it before calling into
any MDIO/PHYLIB related function.

Fixes: ec988ad78ed6 ("phy: Don't increment MDIO bus refcount unless it's a different owner")
Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: stable <stable@vger.kernel.org>  # 4.9+
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/octeon/ethernet.c

@@ -770,6 +770,7 @@ static int cvm_oct_probe(struct platform_device *pdev)
 			/* Initialize the device private structure. */
 			struct octeon_ethernet *priv = netdev_priv(dev);
 
+			SET_NETDEV_DEV(dev, &pdev->dev);
 			dev->netdev_ops = &cvm_oct_pow_netdev_ops;
 			priv->imode = CVMX_HELPER_INTERFACE_MODE_DISABLED;
 			priv->port = CVMX_PIP_NUM_INPUT_PORTS;
@@ -816,6 +817,7 @@ static int cvm_oct_probe(struct platform_device *pdev)
 			}
 
 			/* Initialize the device private structure. */
+			SET_NETDEV_DEV(dev, &pdev->dev);
 			priv = netdev_priv(dev);
 			priv->netdev = dev;
 			priv->of_node = cvm_oct_node_for_port(pip, interface,