dts: zynq: Add basic fdt support

This patch provides a basic fdt support for zynq u-boot.

zynq-7000.dtsi-> initial arch dts file
zynq-zed.dts -> initial zed board dts file
more devices should be added in subsequent patches.

u-boot build: once configuring of a board done
for building dtb with zynq-zed.dts as an input
zynq-uboot> make DEVICE_TREE=zynq-zed

Enabled CONFIG_OF_SEPARATE for building dtb separately.
There is a new binary called u-boot-dtb.bin which is a u-boot
with devicetree supported.

Signed-off-by: Jagannadha Sutradharudu Teki <jaganna@xilinx.com>

arch/arm/dts/zynq-7000.dtsi

@@ -0,0 +1,13 @@
+/*
+ * Xilinx Zynq 7000 DTSI
+ * Describes the hardware common to all Zynq 7000-based boards.
+ *
+ * Copyright (C) 2013 Xilinx, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+/include/ "skeleton.dtsi"
+
+/ {
+	compatible = "xlnx,zynq-7000";
+};

board/xilinx/dts/zynq-zed.dts

@@ -0,0 +1,14 @@
+/*
+ * Xilinx ZED board DTS
+ *
+ * Copyright (C) 2013 Xilinx, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+/dts-v1/;
+#include "zynq-7000.dtsi"
+
+/ {
+	model = "Zynq ZED Board";
+	compatible = "xlnx,zynq-zed", "xlnx,zynq-7000";
+};

include/configs/zynq-common.h

@@ -212,6 +212,11 @@
 #define CONFIG_FIT
 #define CONFIG_FIT_VERBOSE	1 /* enable fit_format_{error,warning}() */
 
+/* FDT support */
+#define CONFIG_OF_CONTROL
+#define CONFIG_OF_SEPARATE
+#define CONFIG_DISPLAY_BOARDINFO_LATE
+
 /* Boot FreeBSD/vxWorks from an ELF image */
 #if defined(CONFIG_ZYNQ_BOOT_FREEBSD)
 # define CONFIG_API