bcm6838: add initial support

This adds the initial support of the Broadcom BCM6838 SoC familly,
only cpu, dram, uart and leds are supported.

Signed-off-by: Philippe Reynes <philippe.reynes@softathome.com>
Reviewed-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/arch/mips/dts/brcm,bcm6838.dtsi b/arch/mips/dts/brcm,bcm6838.dtsi
new file mode 100644
index 0000000..d365d0f
--- /dev/null
+++ b/arch/mips/dts/brcm,bcm6838.dtsi
@@ -0,0 +1,75 @@
+// SPDX-License-Identifier: GPL-2.0+
+/*
+ * Copyright (C) 2018 Philippe Reynes <philippe.reynes@softathome.com>
+ */
+
+#include "skeleton.dtsi"
+
+/ {
+	compatible = "brcm,bcm6838";
+
+	cpus {
+		reg = <0x14e00000 0x4>;
+		#address-cells = <1>;
+		#size-cells = <0>;
+		u-boot,dm-pre-reloc;
+
+		cpu@0 {
+			compatible = "brcm,bcm6838-cpu", "mips,mips4Kc";
+			device_type = "cpu";
+			reg = <0>;
+			u-boot,dm-pre-reloc;
+		};
+
+		cpu@1 {
+			compatible = "brcm,bcm6838-cpu", "mips,mips4Kc";
+			device_type = "cpu";
+			reg = <1>;
+			u-boot,dm-pre-reloc;
+		};
+	};
+
+	clocks {
+		compatible = "simple-bus";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		u-boot,dm-pre-reloc;
+
+		periph_osc: periph-osc {
+			compatible = "fixed-clock";
+			#clock-cells = <0>;
+			clock-frequency = <50000000>;
+			u-boot,dm-pre-reloc;
+		};
+	};
+
+	ubus {
+		compatible = "simple-bus";
+		#address-cells = <1>;
+		#size-cells = <1>;
+		u-boot,dm-pre-reloc;
+
+		memory: memory-controller@12000000 {
+			compatible = "brcm,bcm6328-mc";
+			reg = <0x12000000 0x1000>;
+			u-boot,dm-pre-reloc;
+		};
+
+		uart0: serial@14e00500 {
+			compatible = "brcm,bcm6345-uart";
+			reg = <0x14e00500 0x18>;
+			clocks = <&periph_osc>;
+
+			status = "disabled";
+		};
+
+		leds: led-controller@14e00f00 {
+			compatible = "brcm,bcm6328-leds";
+			reg = <0x14e00f00 0x28>;
+			#address-cells = <1>;
+			#size-cells = <0>;
+
+			status = "disabled";
+		};
+	};
+};