realtek: Fix nvmem support for ethernet device

The function of_get_mac_address is not taking care of evaluation the nvmem
address before trying to read out the mac-address properties. The driver
must check whether the return code is -EPROBE_DEFER and stop the probing
process in that case. If the nvmem-cell related driver code finished, the
probe can be redone ad the correct mac-address will appear for the device.

Signed-off-by: Harshal Gohel <[email protected]>
Signed-off-by: Sharadanand Karanjkar <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/19362
Signed-off-by: Hauke Mehrtens <[email protected]>

target/linux/realtek/files-6.12/drivers/net/ethernet/rtl838x_eth.c

@@ -3500,7 +3500,10 @@ static int __init rtl838x_eth_probe(struct platform_device *pdev)
 	 * 1) from device tree data
 	 * 2) from internal registers set by bootloader
 	 */
-	of_get_mac_address(pdev->dev.of_node, mac_addr);
+	err = of_get_mac_address(pdev->dev.of_node, mac_addr);
+	if (err == -EPROBE_DEFER)
+		return err;
+
 	if (is_valid_ether_addr(mac_addr)) {
 		rtl838x_set_mac_hw(dev, mac_addr);
 	} else {