Remove automatic detection of enterprise modules

We had to move cbauditd due to link issues. This logic isn't
needed anymore.

Change-Id: I354de3c8b058b4733afc3324c84bfb6c4a751802
Reviewed-on: http://review.couchbase.org/43898
Tested-by: buildbot <build@couchbase.com>
Reviewed-by: Daniel Owen <owend@couchbase.com>