devtool: add: properly handle separate build directory
When we were adding a recipe for software that would typically be built
in the same directory as the source, we were always using a separate
build directory unless the user explicitly specified not to, leading to
errors for software that doesn't expect to be built that way (such as
Python modules using distutils). Split out the code that makes this
determination automatically from the "devtool modify" and "devtool
upgrade" code and re-use that here so the behaviour is consistent.
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
