LoongArch: Update dts for Loongson-2K2000 to support GMAC/GNET

Current dts file for Loongson-2K2000's GMAC/GNET is incomplete, both irq
and phy descriptions are missing. Add them to make GMAC/GNET work.
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

arch/loongarch/boot/dts/loongson-2k2000-ref.dts

@@ -61,12 +61,45 @@ &xhci1 {
 
 &gmac0 {
 	status = "okay";
+
+	phy-mode = "gmii";
+	phy-handle = <&phy0>;
+	mdio {
+		compatible = "snps,dwmac-mdio";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		phy0: ethernet-phy@0 {
+			reg = <2>;
+		};
+	};
 };
 
 &gmac1 {
 	status = "okay";
+
+	phy-mode = "gmii";
+	phy-handle = <&phy1>;
+	mdio {
+		compatible = "snps,dwmac-mdio";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		phy1: ethernet-phy@1 {
+			reg = <2>;
+		};
+	};
 };
 
 &gmac2 {
 	status = "okay";
+
+	phy-mode = "rgmii";
+	phy-handle = <&phy2>;
+	mdio {
+		compatible = "snps,dwmac-mdio";
+		#address-cells = <1>;
+		#size-cells = <0>;
+		phy2: ethernet-phy@2 {
+			reg = <0>;
+		};
+	};
 };

arch/loongarch/boot/dts/loongson-2k2000.dtsi

@@ -156,21 +156,27 @@ pcie@1a000000 {
 
 			gmac0: ethernet@3,0 {
 				reg = <0x1800 0x0 0x0 0x0 0x0>;
-				interrupts = <12 IRQ_TYPE_LEVEL_HIGH>;
+				interrupts = <12 IRQ_TYPE_LEVEL_HIGH>,
+					     <13 IRQ_TYPE_LEVEL_HIGH>;
+				interrupt-names = "macirq", "eth_lpi";
 				interrupt-parent = <&pic>;
 				status = "disabled";
 			};
 
 			gmac1: ethernet@3,1 {
 				reg = <0x1900 0x0 0x0 0x0 0x0>;
-				interrupts = <14 IRQ_TYPE_LEVEL_HIGH>;
+				interrupts = <14 IRQ_TYPE_LEVEL_HIGH>,
+					     <15 IRQ_TYPE_LEVEL_HIGH>;
+				interrupt-names = "macirq", "eth_lpi";
 				interrupt-parent = <&pic>;
 				status = "disabled";
 			};
 
 			gmac2: ethernet@3,2 {
 				reg = <0x1a00 0x0 0x0 0x0 0x0>;
-				interrupts = <17 IRQ_TYPE_LEVEL_HIGH>;
+				interrupts = <17 IRQ_TYPE_LEVEL_HIGH>,
+					     <18 IRQ_TYPE_LEVEL_HIGH>;
+				interrupt-names = "macirq", "eth_lpi";
 				interrupt-parent = <&pic>;
 				status = "disabled";
 			};