board: sl28: add DSA support for variant 2

Now that u-boot gained DSA support, and it is already enabled for the
kontron_sl28 board, add the last missing piece and enable the
corresponding devices it in the device tree.
Signed-off-by: NMichael Walle <michael@walle.cc>

arch/arm/dts/fsl-ls1028a-kontron-sl28-var2-u-boot.dtsi

 // SPDX-License-Identifier: GPL-2.0+
 #include "fsl-ls1028a-kontron-sl28-u-boot.dtsi"
+
+/ {
+	aliases {
+		ethernet0 = &mscc_felix_port0;
+		ethernet1 = &mscc_felix_port1;
+	};
+};

arch/arm/dts/fsl-ls1028a-kontron-sl28-var2.dts

@@ -22,4 +22,44 @@
 	/delete-property/ phy-handle;
 };
 
+&enetc2 {
+	status = "okay";
+};
+
+&mscc_felix {
+	status = "okay";
+};
+
+&mscc_felix_port0 {
+	label = "gbe0";
+	phy-handle = <&phy0>;
+	phy-mode = "sgmii";
+	status = "okay";
+};
+
+&mscc_felix_port1 {
+	label = "gbe1";
+	phy-handle = <&phy1>;
+	phy-mode = "sgmii";
+	status = "okay";
+};
+
+&mscc_felix_port4 {
+	ethernet = <&enetc2>;
+	status = "okay";
+};
+
 /delete-node/ &phy0;
+&mdio0 {
+	phy0: ethernet-phy@5 {
+		reg = <0x5>;
+		eee-broken-1000t;
+		eee-broken-100tx;
+	};
+
+	phy1: ethernet-phy@4 {
+		reg = <0x4>;
+		eee-broken-1000t;
+		eee-broken-100tx;
+	};
+};