At least under the current versions of LEED, you do not need to be anything other than a plain vanilla LEED AP to earn IDc2 on any kind of project.
In other words, even though we're being encouraged to upgrade to LEED AP specialties, that is not currently being enforced in a way that would lead you to lose that point on a project. If you have any doubts or concerns about this, check with GBCI—they have the final word.