arm64: dts: marvell: eDPU: add support for version with external switch

New revision of eDPU uses an Marvell MV88E6361 switch to connect the SFP
cage and G.hn IC instead of connecting them directly to the ethernet
controllers.

U-Boot will enable the switch node and disable the unused ethernet
controller.

Signed-off-by: Robert Marko <robert.marko@sartura.hr>
Reviewed-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Gregory CLEMENT <gregory.clement@bootlin.com>

Author: robimarko

arch/arm64/boot/dts/marvell/armada-3720-eDPU.dts

@@ -12,3 +12,50 @@
 &eth0 {
 	phy-mode = "2500base-x";
 };
+
+/*
+ * External MV88E6361 switch is only available on v2 of the board.
+ * U-Boot will enable the MDIO bus and switch nodes.
+ */
+&mdio {
+	status = "disabled";
+	pinctrl-names = "default";
+	pinctrl-0 = <&smi_pins>;
+
+	/* Actual device is MV88E6361 */
+	switch: switch@0 {
+		compatible = "marvell,mv88e6190";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		reg = <0>;
+		status = "disabled";
+
+		ports {
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			port@0 {
+				reg = <0>;
+				label = "cpu";
+				phy-mode = "2500base-x";
+				managed = "in-band-status";
+				ethernet = <&eth0>;
+			};
+
+			port@9 {
+				reg = <9>;
+				label = "downlink";
+				phy-mode = "2500base-x";
+				managed = "in-band-status";
+			};
+
+			port@a {
+				reg = <10>;
+				label = "uplink";
+				phy-mode = "2500base-x";
+				managed = "in-band-status";
+				sfp = <&sfp_eth1>;
+			};
+		};
+	};
+};