ARM: dts: Add initial support for Mediatek mt6582

Add initial support for Mediatek mt6582 and Prestigio
PMT5008 3G tablet, 4 uart, wdt work, init loads successfully. SMP doesn't
work.

Signed-off-by: Maxim Kutnij <[e-mail]>
Link: https://lore.kernel.org/r/[e-mail]
[mb: fix commit subject line]
Signed-off-by: Matthias Brugger <[e-mail]>

arch/arm/boot/dts/mt6582.dtsi

···
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (c) 2021 Maxim Kutnij <[e-mail]>
+ */
+
+#include <dt-bindings/interrupt-controller/irq.h>
+#include <dt-bindings/interrupt-controller/arm-gic.h>
+
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+	compatible = "mediatek,mt6582";
+	interrupt-parent = <&sysirq>;
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu@0 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a7";
+			reg = <0x0>;
+		};
+		cpu@1 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a7";
+			reg = <0x1>;
+		};
+		cpu@2 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a7";
+			reg = <0x2>;
+		};
+		cpu@3 {
+			device_type = "cpu";
+			compatible = "arm,cortex-a7";
+			reg = <0x3>;
+		};
+	};
+
+	system_clk: dummy13m {
+		compatible = "fixed-clock";
+		clock-frequency = <13000000>;
+		#clock-cells = <0>;
+	};
+
+	rtc_clk: dummy32k {
+		compatible = "fixed-clock";
+		clock-frequency = <32000>;
+		#clock-cells = <0>;
+	};
+
+	uart_clk: dummy26m {
+		compatible = "fixed-clock";
+		clock-frequency = <26000000>;
+		#clock-cells = <0>;
+	};
+
+	timer: timer@11008000 {
+		compatible = "mediatek,mt6577-timer";
+		reg = <0x10008000 0x80>;
+		interrupts = <GIC_SPI 112 IRQ_TYPE_LEVEL_LOW>;
+		clocks = <&system_clk>, <&rtc_clk>;
+		clock-names = "system-clk", "rtc-clk";
+	};
+
+	sysirq: interrupt-controller@10200100 {
+		compatible = "mediatek,mt6582-sysirq",
+			     "mediatek,mt6577-sysirq";
+		interrupt-controller;
+		#interrupt-cells = <3>;
+		interrupt-parent = <&gic>;
+		reg = <0x10200100 0x1c>;
+	};
+
+	gic: interrupt-controller@10211000 {
+		compatible = "arm,cortex-a7-gic";
+		interrupt-controller;
+		#interrupt-cells = <3>;
+		interrupt-parent = <&gic>;
+		reg = <0x10211000 0x1000>,
+		      <0x10212000 0x2000>,
+		      <0x10214000 0x2000>,
+		      <0x10216000 0x2000>;
+	};
+
+	uart0: serial@11002000 {
+		compatible = "mediatek,mt6582-uart",
+			     "mediatek,mt6577-uart";
+		reg = <0x11002000 0x400>;
+		interrupts = <GIC_SPI 51 IRQ_TYPE_LEVEL_LOW>;
+		clocks = <&uart_clk>;
+		status = "disabled";
+	};
+
+	uart1: serial@11003000 {
+		compatible = "mediatek,mt6582-uart",
+			     "mediatek,mt6577-uart";
+		reg = <0x11003000 0x400>;
+		interrupts = <GIC_SPI 52 IRQ_TYPE_LEVEL_LOW>;
+		clocks = <&uart_clk>;
+		status = "disabled";
+	};
+
+	uart2: serial@11004000 {
+		compatible = "mediatek,mt6582-uart",
+			     "mediatek,mt6577-uart";
+		reg = <0x11004000 0x400>;
+		interrupts = <GIC_SPI 53 IRQ_TYPE_LEVEL_LOW>;
+		clocks = <&uart_clk>;
+		status = "disabled";
+	};
+
+	uart3: serial@11005000 {
+		compatible = "mediatek,mt6582-uart",
+			     "mediatek,mt6577-uart";
+		reg = <0x11005000 0x400>;
+		interrupts = <GIC_SPI 54 IRQ_TYPE_LEVEL_LOW>;
+		clocks = <&uart_clk>;
+		status = "disabled";
+	};
+
+	watchdog: watchdog@10007000 {
+		compatible = "mediatek,mt6582-wdt",
+			     "mediatek,mt6589-wdt";
+		reg = <0x10007000 0x100>;
+	};
+};