net: ftgmac100: fixed not check status from fixed phy

Add error handling from calling fixed_phy_register.
It may return some error, therefore, need to check the status.

And fixed_phy_register needs to bind a device node for mdio.
Add the mac device node for fixed_phy_register function.
This is a reference to this function, of_phy_register_fixed_link().

Fixes: e24a6c8 ("net: ftgmac100: Get link speed and duplex for NC-SI")
Signed-off-by: Jacky Chou <jacky_chou@aspeedtech.com>
Link: https://patch.msgid.link/20241007032435.787892-1-jacky_chou@aspeedtech.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

drivers/net/ethernet/faraday/ftgmac100.c

@@ -1906,7 +1906,12 @@ static int ftgmac100_probe(struct platform_device *pdev)
 			goto err_phy_connect;
 		}
 
-		phydev = fixed_phy_register(PHY_POLL, &ncsi_phy_status, NULL);
+		phydev = fixed_phy_register(PHY_POLL, &ncsi_phy_status, np);
+		if (IS_ERR(phydev)) {
+			dev_err(&pdev->dev, "failed to register fixed PHY device\n");
+			err = PTR_ERR(phydev);
+			goto err_phy_connect;
+		}
 		err = phy_connect_direct(netdev, phydev, ftgmac100_adjust_link,
 					 PHY_INTERFACE_MODE_MII);
 		if (err) {