Update zephyr integration of openthread to latest api as of 2018-12-17:
2a75d30684
Both echo_server and echo_client compile and are operational.
Signed-off-by: Martin Turon <mturon@google.com>
OpenThread requires platform definition with standarized API
so we have to add wrappers to make it compatible with Zephyr.
OpenThread is based on autoconf, this requires
more specific CMakeLists.txt which allows to clone specific
commit or point to local copy of openthread.
Signed-off-by: Kamil Sroka <kamil.sroka@nordicsemi.no>