ramips: use fixed layout cell "mac-base" for Netgear R6220

This drops a use of downstream "mac-address-increment".

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>

target/linux/ramips/dts/mt7621_netgear_r6220.dts

@@ -47,11 +47,16 @@
 			reg = <0x2e00000 0x100000>;
 			read-only;
 
-			#address-cells = <1>;
-			#size-cells = <1>;
+			nvmem-layout {
+				compatible = "fixed-layout";
+				#address-cells = <1>;
+				#size-cells = <1>;
 
-			macaddr_factory_4: macaddr@4 {
-				reg = <0x4 0x6>;
+				macaddr_factory_4: macaddr@4 {
+					compatible = "mac-base";
+					reg = <0x4 0x6>;
+					#nvmem-cell-cells = <1>;
+				};
 			};
 		};
 
@@ -64,12 +69,11 @@
 };
 
 &gmac0 {
-	nvmem-cells = <&macaddr_factory_4>;
+	nvmem-cells = <&macaddr_factory_4 0>;
 	nvmem-cell-names = "mac-address";
 };
 
 &gmac1 {
-	nvmem-cells = <&macaddr_factory_4>;
+	nvmem-cells = <&macaddr_factory_4 1>;
 	nvmem-cell-names = "mac-address";
-	mac-address-increment = <1>;
 };