ath79: add support for Mikrotik LHG 5

The MikroTik LHG 5 series (product codes RBLHG-5nD, RBLHG-5HPnD and
RBLHG-5HPnD-XL) devices are an outdoor 5GHz CPE with a 24.5dBi or 27dBi
integrated antenna built around the Atheros AR9344 SoC.
It is very similar to the SXT Lite5 series which this patch is based
upon.

Specifications:
 - SoC: Atheros AR9344
 - RAM: 64 MB
 - Storage: 16 MB SPI NOR
 - Wireless: Atheros AR9340 (SoC) 802.11a/n 2x2:2
 - Ethernet: Atheros AR8229 switch (SoC), 1x 10/100 port,
    8-32 Vdc PoE in
 - 8 user-controllable LEDs:
  - 1x power (blue)
  - 1x user (white)
  - 1x ethernet (green)
  - 5x rssi (green)

 See https://mikrotik.com/product/RBLHG-5nD for more details.

Notes:
 The device was already supported in the ar71xx target.

Flashing:
 TFTP boot initramfs image and then perform a sysupgrade. Follow common
 MikroTik procedure as in https://openwrt.org/toh/mikrotik/common.

Signed-off-by: Jakob (Jack/XDjackieXD) <jakob@chaosfield.at>

target/linux/ath79/dts/ar9344_mikrotik_routerboard-16m-nor.dtsi

@@ -0,0 +1,65 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "ar9344.dtsi"
+
+&spi {
+	status = "okay";
+
+	flash@0 {
+		compatible = "jedec,spi-nor";
+		reg = <0>;
+		spi-max-frequency = <40000000>;
+
+		partitions {
+			compatible = "fixed-partitions";
+			#address-cells = <1>;
+			#size-cells = <1>;
+
+			partition@0 {
+				label = "RouterBoot";
+				reg = <0x0 0x20000>;
+				read-only;
+				compatible = "mikrotik,routerboot-partitions";
+				#address-cells = <1>;
+				#size-cells = <1>;
+
+				partition@0 {
+					label = "bootloader1";
+					reg = <0x0 0x0>;
+					read-only;
+				};
+
+				hard_config: hard_config {
+					read-only;
+				};
+
+				bios {
+					size = <0x1000>;
+					read-only;
+				};
+
+				partition@10000 {
+					label = "bootloader2";
+					reg = <0x10000 0x0>;
+					read-only;
+				};
+
+				soft_config {
+					label = "soft_config";
+				};
+			};
+
+			partition@20000 {
+				compatible = "mikrotik,minor";
+				label = "firmware";
+				reg = <0x020000 0xfe0000>;
+			};
+		};
+	};
+};
+
+&wmac {
+	status = "okay";
+
+	qca,no-eeprom;
+};

target/linux/ath79/dts/ar9344_mikrotik_routerboard-lhg-5nd.dts

@@ -0,0 +1,91 @@
+// SPDX-License-Identifier: GPL-2.0-or-later OR MIT
+
+#include "ar9344_mikrotik_routerboard-16m-nor.dtsi"
+
+#include <dt-bindings/gpio/gpio.h>
+#include <dt-bindings/input/input.h>
+
+/ {
+	compatible = "mikrotik,routerboard-lhg-5nd", "qca,ar9344";
+	model = "MikroTik LHG 5nD platform";
+
+	aliases {
+		led-boot = &led_user;
+		led-failsafe = &led_user;
+		led-running = &led_user;
+		led-upgrade = &led_user;
+	};
+
+	leds {
+		compatible = "gpio-leds";
+
+		power {
+			label = "blue:power";
+			gpios = <&gpio 11 GPIO_ACTIVE_HIGH>;
+			default-state = "on";
+		};
+
+		rssilow {
+			label = "green:rssilow";
+			gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
+		};
+
+		rssimediumlow {
+			label = "green:rssimediumlow";
+			gpios = <&gpio 12 GPIO_ACTIVE_LOW>;
+		};
+
+		rssimedium {
+			label = "green:rssimedium";
+			gpios = <&gpio 4 GPIO_ACTIVE_LOW>;
+		};
+
+		rssimediumhigh {
+			label = "green:rssimediumhigh";
+			gpios = <&gpio 21 GPIO_ACTIVE_LOW>;
+		};
+
+		rssihigh {
+			label = "green:rssihigh";
+			gpios = <&gpio 18 GPIO_ACTIVE_LOW>;
+		};
+
+		led_user: user {
+			label = "white:user";
+			gpios = <&gpio 20 GPIO_ACTIVE_LOW>;
+		};
+
+		lan {
+			label = "green:lan";
+			gpios = <&gpio 14 GPIO_ACTIVE_LOW>;
+		};
+	};
+
+	keys {
+		compatible = "gpio-keys";
+
+		reset {
+			label = "reset";
+			linux,code = <KEY_RESTART>;
+			gpios = <&gpio 15 GPIO_ACTIVE_LOW>;
+			debounce-interval = <60>;
+		};
+	};
+};
+
+&eth0 {
+	status = "okay";
+
+	phy-handle = <&swphy0>;
+
+	gmac-config {
+		device = <&gmac>;
+		switch-phy-swap = <1>;
+	};
+};
+
+&eth1 {
+	status = "okay";
+
+	compatible = "syscon", "simple-mfd";
+};