The Sphinx .. only:: directive is limited to handling only conditional
text and can't handling conditional use of directives. For example,
.. only:: test
.. automodule:: west.runners.core
:members:
is not handled. This PR monkey patches the handling of the existing
.. only:: directive done by Sphinx.
See https://github.com/pfalcon/sphinx_selective_exclude for details.
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>