This documentation is needed for developers who are porting new boards.
Fixing #5577
Signed-off-by: Andrzej Puzdrowski <andrzej.puzdrowski@nordicsemi.no>
Since we moved around where yaml, dts, and fixup files exist we need to
update the docs to reflect those changes. Also, try and make the docs
at little more generic to changes that are occuring.
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>