Interesting screen name for a Belgian--the name of a recent King!
I would say, in most instances, that I wouldn't disclose that I have Asperger's.
It's true: discrimination is not allowed--but, alas, gossip has never been banned in offices!
I would greet, for the most part, people who are in your department. If somebody is in a different department (unless you have day-to-day dealings with that person), I wouldn't feel obligated to greet that person.