ARM: dts: BCM5301X: provide address for SoC MACs on ASUS RT-AC3100 & AC88U

Do not leave the providing of a MAC address for an SoC MAC to a driver.
Describe it on the bindings. Provide a distinct MAC address for each SoC
MAC.

Signed-off-by: Arınç ÜNAL <arinc.unal@arinc9.com>
Link: https://lore.kernel.org/r/20240414-for-soc-asus-rt-ac3100-improvements-v1-2-0e40caf1a70a@arinc9.com
Signed-off-by: Florian Fainelli <florian.fainelli@broadcom.com>

Author: arinc9

arch/arm/boot/dts/broadcom/bcm47094-asus-rt-ac3100.dts

@@ -13,11 +13,22 @@
 
 	nvram@1c080000 {
 		et0macaddr: et0macaddr {
+			#nvmem-cell-cells = <1>;
 		};
 	};
 };
 
 &gmac0 {
-	nvmem-cells = <&et0macaddr>;
+	nvmem-cells = <&et0macaddr 0>;
+	nvmem-cell-names = "mac-address";
+};
+
+&gmac1 {
+	nvmem-cells = <&et0macaddr 1>;
+	nvmem-cell-names = "mac-address";
+};
+
+&gmac2 {
+	nvmem-cells = <&et0macaddr 2>;
 	nvmem-cell-names = "mac-address";
 };

arch/arm/boot/dts/broadcom/bcm47094-asus-rt-ac88u.dts

@@ -13,6 +13,7 @@
 
 	nvram@1c080000 {
 		et1macaddr: et1macaddr {
+			#nvmem-cell-cells = <1>;
 		};
 	};
 
@@ -117,6 +118,11 @@
 };
 
 &gmac1 {
-	nvmem-cells = <&et1macaddr>;
+	nvmem-cells = <&et1macaddr 0>;
+	nvmem-cell-names = "mac-address";
+};
+
+&gmac2 {
+	nvmem-cells = <&et1macaddr 1>;
 	nvmem-cell-names = "mac-address";
 };