MIPS: xilfpga: Add xilfpga device tree files.

Add device tree files for the MIPSfpga platform.

See Documentation/devicetree/bindings/mips/img/xilfpga.txt
for details about MIPSfpga

Signed-off-by: Zubair Lutfullah Kakakhel <[e-mail]>
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Cc: [e-mail]
Patchwork: https://patchwork.linux-mips.org/patch/11362/
Signed-off-by: Ralf Baechle <[e-mail]>

arch/mips/boot/dts/Makefile

···
 dts-dirs	+= netlogic
 dts-dirs	+= qca
 dts-dirs	+= ralink
+dts-dirs	+= xilfpga
 
 obj-y		:= $(addsuffix /, $(dts-dirs))
 

arch/mips/boot/dts/xilfpga/Makefile

···
+dtb-$(CONFIG_XILFPGA_NEXYS4DDR)	+= nexys4ddr.dtb
+
+obj-y				+= $(patsubst %.dtb, %.dtb.o, $(dtb-y))
+
+# Force kbuild to make empty built-in.o if necessary
+obj-				+= dummy.o
+
+always				:= $(dtb-y)
+clean-files	:= *.dtb *.dtb.S

arch/mips/boot/dts/xilfpga/microAptiv.dtsi

···
+/ {
+	#address-cells = <1>;
+	#size-cells = <1>;
+	compatible = "img,xilfpga";
+
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+		cpu@0 {
+			device_type = "cpu";
+			compatible = "mips,m14Kc";
+			clocks	= <&ext>;
+			reg = <0>;
+		};
+	};
+
+	ext: ext {
+		compatible = "fixed-clock";
+		#clock-cells = <0>;
+	};
+};

arch/mips/boot/dts/xilfpga/nexys4ddr.dts

···
+/dts-v1/;
+
+#include "microAptiv.dtsi"
+
+/ {
+	compatible = "digilent,nexys4ddr";
+
+	memory {
+		device_type = "memory";
+		reg = <0x0 0x08000000>;
+	};
+
+	cpuintc: interrupt-controller@0 {
+		#address-cells = <0>;
+		#interrupt-cells = <1>;
+		interrupt-controller;
+		compatible = "mti,cpu-interrupt-controller";
+	};
+
+	axi_gpio: gpio@10600000 {
+		#gpio-cells = <1>;
+		compatible = "xlnx,xps-gpio-1.00.a";
+		gpio-controller;
+		reg = <0x10600000 0x10000>;
+		xlnx,all-inputs = <0x0>;
+		xlnx,dout-default = <0x0>;
+		xlnx,gpio-width = <0x16>;
+		xlnx,interrupt-present = <0x0>;
+		xlnx,is-dual = <0x0>;
+		xlnx,tri-default = <0xffffffff>;
+	} ;
+
+	axi_uart16550: serial@10400000 {
+		compatible = "ns16550a";
+		reg = <0x10400000 0x10000>;
+
+		reg-shift = <2>;
+		reg-offset = <0x1000>;
+
+		clocks	= <&ext>;
+	};
+};
+
+&ext {
+	clock-frequency = <50000000>;
+};