Add Support for HLK-7621 Router Designed By Me (#9194)

* add support for hilink_hlk-7621a

* add dts of mt7621_hilink_hlk-7621a

target/linux/ramips/dts/mt7621_hilink_hlk-7621a.dts

@@ -0,0 +1,113 @@
+// SPDX-License-Identifier: GPL-2.0-or-later
+/dts-v1/;
+
+#include "mt7621.dtsi"
+
+/ {
+	compatible = "hilink,hlk-7621a", "mediatek,mt7621-soc";
+	model = "HiLink HLK-7621A";
+
+	chosen {
+		bootargs = "console=ttyS0,57600";
+	};
+};
+
+&spi0 {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <44000000>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "u-boot";
+				reg = <0x0 0x30000>;
+				read-only;
+			};
+
+			partition@30000 {
+				label = "u-boot-env";
+				reg = <0x30000 0x10000>;
+				read-only;
+			};
+
+			factory: partition@40000 {
+				label = "factory";
+				reg = <0x40000 0x10000>;
+				read-only;
+			};
+
+			partition@50000 {
+				compatible = "denx,uimage";
+				label = "firmware";
+				reg = <0x50000 0x1fb0000>;
+			};
+		};
+	};
+};
+
+&switch0 {
+	ports {
+		port@0 {
+			status = "okay";
+			label = "lan1";
+		};
+
+		port@1 {
+			status = "okay";
+			label = "lan2";
+		};
+
+		port@2 {
+			status = "okay";
+			label = "lan3";
+		};
+
+		port@3 {
+			status = "okay";
+			label = "lan4";
+		};
+
+		port@4 {
+			status = "okay";
+			label = "wan";
+		};
+	};
+};
+
+&gmac0 {
+	mtd-mac-address = <&factory 0x8004>;
+};
+
+&state_default {
+	gpio {
+		groups = "rgmii2", "jtag";
+		function = "gpio";
+	};
+};
+
+&uartlite2 {
+    status = "okay";
+};
+
+&uartlite3 {
+    status = "okay";
+};
+
+&xhci {
+    status = "okay";
+};
+
+&sdhci {
+    status = "okay";
+};
+
+&i2c {
+    status = "okay";
+};

target/linux/ramips/image/mt7621.mk

@@ -672,6 +672,14 @@ define Device/gnubee_gb-pc2
 endef
 TARGET_DEVICES += gnubee_gb-pc2
 
+define Device/hilink_hlk-7621a
+  IMAGE_SIZE := 32448k
+  DEVICE_VENDOR := HiLink
+  DEVICE_MODEL := HLK-7621A
+  DEVICE_PACKAGES := kmod-usb3
+endef
+TARGET_DEVICES += hilink_hlk-7621a
+
 define Device/hiwifi_hc5962
   $(Device/dsa-migration)
   BLOCKSIZE := 128k