net: lan966x: Convert to devm_of_phy_optional_get()

Use the new devm_of_phy_optional_get() helper instead of open-coding the
same operation.

Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Steen Hegelund <Steen.Hegelund@microchip.com>
Link: https://lore.kernel.org/r/993b0f4ac5b84b2b72223011614d2e821f9e7302.1674584626.git.geert+renesas@glider.be
Signed-off-by: Vinod Koul <vkoul@kernel.org>

Author: geertu

drivers/net/ethernet/microchip/lan966x/lan966x_main.c

@@ -1147,9 +1147,8 @@ static int lan966x_probe(struct platform_device *pdev)
 		lan966x->ports[p]->config.portmode = phy_mode;
 		lan966x->ports[p]->fwnode = fwnode_handle_get(portnp);
 
-		serdes = devm_of_phy_get(lan966x->dev, to_of_node(portnp), NULL);
-		if (PTR_ERR(serdes) == -ENODEV)
-			serdes = NULL;
+		serdes = devm_of_phy_optional_get(lan966x->dev,
+						  to_of_node(portnp), NULL);
 		if (IS_ERR(serdes)) {
 			err = PTR_ERR(serdes);
 			goto cleanup_ports;