Track removal of Tokenring and FDDI media types from devd.cc.

Fixes: eec02418d83b Remove support for FDDI and token ring media types in userland utilities.

Reviewed by: brooks, gjb, imp

Approved by: brooks (src), gjb (mentor, src), imp (src)

Differential Revision: https://reviews.freebsd.org/D36668

MFC after: 3 days