Register the dicom dissector by name so it can be used with SSL.

Bug: 10450
Change-Id: I786de3de39c6d4829135b67a64936c28757d1ff4
Reviewed-on: https://code.wireshark.org/review/4038
Reviewed-by: Evan Huus <eapache@gmail.com>
Reviewed-by: Anders Broman <a.broman58@gmail.com>