arm: dts: ls1028a: declare the fixed-link speeds for the internal ENETC ports

To comply with the device tree bindings expectations for an Ethernet
controller, as well as to simplify the driver code, declare fixed-link
nodes for the internal ENETC ports (attached to the mscc_felix switch).

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Reviewed-by: Ramon Fried <rfried.dev@gmail.com>

arch/arm/dts/fsl-ls1028a.dtsi

@@ -144,12 +144,22 @@
 			reg = <0x000200 0 0 0 0>;
 			status = "okay";
 			phy-mode = "internal";
+
+			fixed-link {
+				speed = <2500>;
+				full-duplex;
+			};
 		};
 		mdio0: pci@0,3 {
 			#address-cells=<0>;
 			#size-cells=<1>;
 			reg = <0x000300 0 0 0 0>;
 			status = "disabled";
+
+			fixed-link {
+				speed = <1000>;
+				full-duplex;
+			};
 		};
 
 		mscc_felix: pci@0,5 {