CDH does not come with the Kafka parcel. You need to add that seperately. Check the list of available parcels. If it is not present add the remote repo for CDH Kafka and check for new parcels. If it is available, download, distribute, and activate.
From CM Add a Service Wizard:
"Apache Kafka is publish-subscribe messaging rethought as a distributed commit log. Before adding this service, ensure that either the Kafka parcel is activated or the Kafka package is installed."