Well, you have a couple of options. Either you can go to the Uni welfare people and request that they make him priority for self contained accomodation (which he should be- my Son has AS and there's no way he could do halls), or you can sit him down and say straight - 'We've enjoyed having you here for X long, but it is time now for you to move on.'. You could add 'How can I help you to do this' if you want, don't say 'I'll do what I can to help'- coz to him that means letting him stay put! If he was NT he might alter his routines, but that is frankly highly unlikely here
The NAS website (National Autistic Sociry) offer a telephone helpline where they could advise you what he should be entitled to in regards to accomodation etc.
However, he IS 30! It really is hias responsibility to inform Uni about this, Uni's tend to make a priority of people who disclose these things when hall allocation first comes up, but they have their hands tied once it has all been allocated.
You DO have the option of calling his Dad too. He could contact the Council regarding a flatlet or whatever is deemed appropriate.
Most Uni's have a mature student advisor, student support or someone outside accomodation services that would be an appropriate contact- deatils should be on their website.
Finally, I think you are GREAT for being so supportive of him, but do remember he isn't your responsibility. The Uni , Social Services, his Father... whatever, they all need to be doing more to help this man with what is, at the end of the day, a fairly typical AS dilemma.