ARM: dts: cygnus: add ethernet0 alias

In order to avoid Linux generating a random mac address on every boot,
add an ethernet0 alias that will allow u-boot to patch the dtb with
the MAC address.
Signed-off-by: NClément Péron <peron.clem@gmail.com>
Acked-by: NScott Branden <scott.branden@broadcom.com>
Signed-off-by: NFlorian Fainelli <f.fainelli@gmail.com>

arch/arm/boot/dts/bcm-cygnus.dtsi

@@ -41,6 +41,10 @@
 	model = "Broadcom Cygnus SoC";
 	interrupt-parent = <&gic>;
 
+	aliases {
+		ethernet0 = &eth0;
+	};
+
 	cpus {
 		#address-cells = <1>;
 		#size-cells = <0>;