I'm not in college, but I go to a private high school where you also disclose disabilities in the same way. I chose to do that, and so the learning specialist at my school has communicated with my teachers exactly my diagnosises, how they affect my learning, and what accommodations I get. Whether or not I use those accommodations is up to me. But the teachers are aware of my situation.

I think that self disclosure is a good thing. If you have a history of using accommodations, it will be much less likely to be looked at as an excuse if it turns out that you do end up needing that extra help. Just because you tell your professor about your issues doesn't mean that you expect special treatment, and your professor knows that. I think if anything, he/she will be glad to know because then they will be better able to help you if you need it.