Move OpenThread's glue code along with the Kconfig files that configure
OpenThread stack itself into module directory.
Update the maintainers file to reflect this change.
Signed-off-by: Robert Lubos <robert.lubos@nordicsemi.no>
This commit moves openthread CMakeLists.txt from openthread submodule
to zephyr/modules/openthread.
Signed-off-by: Przemyslaw Bida <przemyslaw.bida@nordicsemi.no>