powerpc: dts: Enable device tree support for T2080QDS

Add device tree for T2080QDS board and enable CONFIG_OF_CONTROL
so that device tree can be compiled.

Update board README for device tree usage.

Signed-off-by: Jagdish Gediya <jagdish.gediya@nxp.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: York Sun <york.sun@nxp.com>
diff --git a/board/freescale/t208xqds/README b/board/freescale/t208xqds/README
index 2a2a0e5..d690857 100755
--- a/board/freescale/t208xqds/README
+++ b/board/freescale/t208xqds/README
@@ -272,3 +272,22 @@
 
 For more details, please refer to T2080QDS User Guide and access
 website www.freescale.com and Freescale QorIQ SDK Infocenter document.
+
+Device tree support and how to enable it for different configs
+--------------------------------------------------------------
+Device tree support is available for t2080qds for below mentioned boot,
+1. NOR Boot
+2. NAND Boot
+3. SD Boot
+4. SPIFLASH Boot
+
+To enable device tree support for other boot, below configs need to be
+enabled in relative defconfig file,
+1. CONFIG_DEFAULT_DEVICE_TREE="t2080qds" (Change default device tree name if required)
+2. CONFIG_OF_CONTROL
+3. CONFIG_MPC85XX_HAVE_RESET_VECTOR if reset vector is located at
+   CONFIG_RESET_VECTOR_ADDRESS - 0xffc
+
+If device tree support is enabled in defconfig,
+1. use 'u-boot-with-dtb.bin' for NOR boot.
+2. use 'u-boot-with-spl-pbl.bin' for other boot.