build: Update base build files to add in device tree support

Update main CMakeLists.txt, module\CMakeLists.txt  and framework\CMakeLists.txt
to support additional steps for device tree configuration support.

Add cmake/dts.cmake to implement tool flow for this support.

Devicetree build is triggered by .dts file in target build.

Signed-off-by: Mike Leach <mike.leach@linaro.org>