tegra: nyan-big: Add a .its file for chromium

Add a sample .its file for booting U-Boot on a nyan-big Chromebook.

Signed-off-by: Simon Glass <sjg@chromium.org>

doc/chromium/nyan-big.its

+/dts-v1/;
+
+/ {
+	description = "U-Boot mainline";
+	#address-cells = <1>;
+
+	images {
+		kernel@1 {
+			description = "U-Boot mainline";
+			type = "kernel_noload";
+			arch = "arm";
+			os = "linux";
+			data = /incbin/("../.././b/nyan-big/u-boot.bin");
+			compression = "none";
+			load = <0>;
+			entry = <0>;
+			hash@2 {
+				algo = "sha1";
+			};
+		};
+
+		fdt@1{
+			description = "tegra124-nyan-big.dtb";
+			data = /incbin/("../.././b/nyan-big/u-boot.dtb");
+			type = "flat_dt";
+			arch = "arm";
+			compression = "none";
+			hash@1{
+				algo = "sha1";
+			};
+		};
+	};
+
+	configurations {
+		default = "config@1";
+		config@1 {
+			description = "Boot U-Boot";
+			kernel = "kernel@1";
+			fdt = "fdt@1";
+		};
+	};
+};