kernel: rtl836x: change missing mdio node log level to info

mdio node is optional for the rtl836x switch. Some devices use GPIO to
control the switch chip. Missing mdio is a normal behavior.

Signed-off-by: Shiji Yang <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/21143
Signed-off-by: Hauke Mehrtens <[email protected]>

target/linux/generic/files/drivers/net/phy/rtl8366_smi.c

@@ -1489,7 +1489,7 @@ static int rtl8366_smi_probe_of(struct platform_device *pdev, struct rtl8366_smi
 
 	mdio_node = of_parse_phandle(np, "mii-bus", 0);
 	if (!mdio_node) {
-		dev_err(&pdev->dev, "cannot find mdio node phandle");
+		dev_info(&pdev->dev, "cannot find mdio node phandle");
 		goto try_gpio;
 	}