ARM: dts: imx: add nitrogen6x board

Add file imx6q-nitrogen6x.dts,
	imx6dl-nitrogen6x.dts,
	imx6qdl-nitrogen6x.dtsi

And add board to makefile.

Eric Nelson created a web page to show the
differences between Nitrogen6x and Sabre Lite boards.
http://boundarydevices.com/differences-sabre-lite-nitrogen6x

Signed-off-by: Troy Kisky <troy.kisky@boundarydevices.com>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>

arch/arm/boot/dts/imx6dl-nitrogen6x.dts

@@ -0,0 +1,21 @@
+/*
+ * Copyright 2013 Boundary Devices, Inc.
+ * Copyright 2012 Freescale Semiconductor, Inc.
+ * Copyright 2011 Linaro Ltd.
+ *
+ * The code contained herein is licensed under the GNU General Public
+ * License. You may obtain a copy of the GNU General Public License
+ * Version 2 or later at the following locations:
+ *
+ * http://www.opensource.org/licenses/gpl-license.html
+ * http://www.gnu.org/copyleft/gpl.html
+ */
+
+/dts-v1/;
+#include "imx6dl.dtsi"
+#include "imx6qdl-nitrogen6x.dtsi"
+
+/ {
+	model = "Freescale i.MX6 DualLite Nitrogen6x Board";
+	compatible = "fsl,imx6dl-nitrogen6x", "fsl,imx6dl";
+};