arm64: dts: marvell: add xmdio nodes for 7k/8k

Add the description of the xMDIO bus for the Marvell Armada 7k and
Marvell Armada 8k; for both CP110 slave and master. This bus is found
on Marvell Ethernet controllers and provides an interface with the
xMDIO bus.
Signed-off-by: Antoine Tenart <antoine.tenart@free-electrons.com>
Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com>

arch/arm64/boot/dts/marvell/armada-cp110-master.dtsi

@@ -98,6 +98,14 @@ cpm_mdio: mdio@12a200 {
 				status = "disabled";
 			};
 
+			cpm_xmdio: mdio@12a600 {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				compatible = "marvell,xmdio";
+				reg = <0x12a600 0x10>;
+				status = "disabled";
+			};
+
 			cpm_syscon0: system-controller@440000 {
 				compatible = "marvell,cp110-system-controller0",
 					     "syscon";

arch/arm64/boot/dts/marvell/armada-cp110-slave.dtsi

@@ -105,6 +105,14 @@ cps_mdio: mdio@12a200 {
 				status = "disabled";
 			};
 
+			cps_xmdio: mdio@12a600 {
+				#address-cells = <1>;
+				#size-cells = <0>;
+				compatible = "marvell,xmdio";
+				reg = <0x12a600 0x10>;
+				status = "disabled";
+			};
+
 			cps_syscon0: system-controller@440000 {
 				compatible = "marvell,cp110-system-controller0",
 					     "syscon";