NDB (MySQL Cluster) has been removed completely from MariaDB 10.1. From MariaDB 10.0 and below, it was disabled due to it not being in the main upstream MySQL releases. Upstream has NDB available as a separate download, because Cluster is updated more frequently compared to baseline MySQL.
For an actively developed alternative, see Galera Cluster.
One of the prerequisites to having NDB working in MariaDB is for us to get an active maintainer of the NDB code.
In 'theory' it should be easy for anyone to get ndb in MariaDB to work as well as in MySQL as all the ndb code is still in the tree. If you are interested in (and capable of) doing this, please join the MariaDB project!