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/arch/powerpc/dts/Makefile b/arch/powerpc/dts/Makefile
index de14e7b..a19aa56 100644
--- a/arch/powerpc/dts/Makefile
+++ b/arch/powerpc/dts/Makefile
@@ -1,5 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0+
 
+dtb-$(CONFIG_TARGET_T2080QDS) += t2080qds.dtb
+
 targets += $(dtb-y)
 
 # Add any required device tree compiler flags here