ath79: drop unused/incomplete dts

These dts itself are incomplete (e.g. missing mtd partitions) and its
deivce support is never added to ath79 target.
Drop these unused dts for now.

Signed-off-by: Chuanhong Guo <gch981213@gmail.com>

target/linux/ath79/dts/ar9331_dptechnics_dpt-module.dts

@@ -1,69 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/dts-v1/;
-
-#include <dt-bindings/gpio/gpio.h>
-#include <dt-bindings/input/input.h>
-
-#include "ar9331.dtsi"
-
-/ {
-	model = "DPTechnics DPT-Module";
-	compatible = "dptechnics,dpt-module", "qca,ar9331";
-
-	aliases {
-		serial0 = &uart;
-	};
-
-	leds {
-		compatible = "gpio-leds";
-
-		system {
-			label = "dpt-module:green:system";
-			gpios = <&gpio 27 GPIO_ACTIVE_LOW>;
-		};
-	};
-
-	keys {
-		compatible = "gpio-keys-polled";
-		poll-interval = <100>;
-
-		button0 {
-			label = "reset";
-			linux,code = <KEY_RESTART>;
-			gpios = <&gpio 11 GPIO_ACTIVE_LOW>;
-		};
-	};
-};
-
-&ref {
-	clock-frequency = <25000000>;
-};
-
-&uart {
-	status = "okay";
-};
-
-&gpio {
-	status = "okay";
-};
-
-&usb {
-	dr_mode = "host";
-	status = "okay";
-};
-
-&usb_phy {
-	status = "okay";
-};
-
-&spi {
-	num-chipselects = <1>;
-	status = "okay";
-
-	/* Winbond 25Q128FVSG SPI flash */
-	flash@0 {
-		compatible = "winbond,w25q128", "jedec,spi-nor";
-		spi-max-frequency = <104000000>;
-		reg = <0>;
-	};
-};

target/linux/ath79/dts/ar9331_dragino_ms14.dts

@@ -1,92 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/dts-v1/;
-
-#include <dt-bindings/gpio/gpio.h>
-#include <dt-bindings/input/input.h>
-
-#include "ar9331.dtsi"
-
-/ {
-	model = "Dragino MS14 (Dragino 2)";
-	compatible = "dragino,ms14", "qca,ar9331";
-
-	aliases {
-		serial0 = &uart;
-	};
-
-	leds {
-		compatible = "gpio-leds";
-		pinctrl-names = "default";
-		pinctrl-0 = <&switch_led_disable_pins>;
-
-		wlan {
-			label = "dragino2:red:wlan";
-			gpios = <&gpio 0 GPIO_ACTIVE_HIGH>;
-		};
-
-		lan {
-			label = "dragino2:red:lan";
-			gpios = <&gpio 13 GPIO_ACTIVE_LOW>;
-		};
-
-		wan {
-			label = "dragino2:red:wan";
-			gpios = <&gpio 17 GPIO_ACTIVE_LOW>;
-		};
-
-		system {
-			label = "dragino2:red:system";
-			gpios = <&gpio 28 GPIO_ACTIVE_HIGH>;
-		};
-	};
-
-	keys {
-		compatible = "gpio-keys-polled";
-		poll-interval = <100>;
-
-		button0 {
-			label = "jumpstart";
-			linux,code = <KEY_WPS_BUTTON>;
-			gpios = <&gpio 11 GPIO_ACTIVE_LOW>;
-		};
-
-		button1 {
-			label = "reset";
-			linux,code = <KEY_RESTART>;
-			gpios = <&gpio 12 GPIO_ACTIVE_LOW>;
-		};
-	};
-};
-
-&ref {
-	clock-frequency = <25000000>;
-};
-
-&uart {
-	status = "okay";
-};
-
-&gpio {
-	status = "okay";
-};
-
-&usb {
-	dr_mode = "host";
-	status = "okay";
-};
-
-&usb_phy {
-	status = "okay";
-};
-
-&spi {
-	num-chipselects = <1>;
-	status = "okay";
-
-	/* Winbond 25Q128BVFG SPI flash */
-	flash@0 {
-		compatible = "winbond,w25q128", "jedec,spi-nor";
-		spi-max-frequency = <104000000>;
-		reg = <0>;
-	};
-};

target/linux/ath79/dts/ar9331_onion_omega.dts

@@ -1,69 +0,0 @@
-// SPDX-License-Identifier: GPL-2.0
-/dts-v1/;
-
-#include <dt-bindings/gpio/gpio.h>
-#include <dt-bindings/input/input.h>
-
-#include "ar9331.dtsi"
-
-/ {
-	model = "Onion Omega";
-	compatible = "onion,omega", "qca,ar9331";
-
-	aliases {
-		serial0 = &uart;
-	};
-
-	leds {
-		compatible = "gpio-leds";
-
-		system {
-			label = "onion:amber:system";
-			gpios = <&gpio 27 GPIO_ACTIVE_LOW>;
-		};
-	};
-
-	keys {
-		compatible = "gpio-keys-polled";
-		poll-interval = <100>;
-
-		button0 {
-			label = "reset";
-			linux,code = <KEY_RESTART>;
-			gpios = <&gpio 11 GPIO_ACTIVE_HIGH>;
-		};
-	};
-};
-
-&ref {
-	clock-frequency = <25000000>;
-};
-
-&uart {
-	status = "okay";
-};
-
-&gpio {
-	status = "okay";
-};
-
-&usb {
-	dr_mode = "host";
-	status = "okay";
-};
-
-&usb_phy {
-	status = "okay";
-};
-
-&spi {
-	num-chipselects = <1>;
-	status = "okay";
-
-	/* Winbond 25Q128FVSG SPI flash */
-	flash@0 {
-		compatible = "winbond,w25q128", "jedec,spi-nor";
-		spi-max-frequency = <104000000>;
-		reg = <0>;
-	};
-};