ipq40xx: add label-mac-device alias for Linksys WHW01

Set the label-mac-device to be able to easily fetch the mac-address of
the device, which is printed on the bottom of the case.
While at it, remove the TODO - the ethernet0 alias is needed to get the
mac from bootloader.

Signed-off-by: Christoph Krapp <achterin@gmail.com>
Link: https://github.com/openwrt/openwrt/pull/20441
Signed-off-by: Robert Marko <robimarko@gmail.com>
(cherry picked from commit deca8fd24b)
Link: https://github.com/openwrt/openwrt/pull/20454
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>

target/linux/ipq40xx/files-6.6/arch/arm/boot/dts/qcom/qcom-ipq4018-whw01.dts

@@ -10,11 +10,11 @@
 	compatible = "linksys,whw01";
 
 	aliases {
-		// TODO: Verify if the ethernet0 alias is needed
 		ethernet0 = &gmac;
 		serial0 = &blsp1_uart1;
 		led-boot = &led_system_blue;
 		led-running = &led_system_blue;
+		label-mac-device = &gmac;
 	};
 
 	chosen {