As a graduating college student myself, I learned fast that higher education lags behind other levels of education in mental health or intellectual disabilities. Most colleges believe that anyone with autism simply does not get admitted. This is probably still true of lower-functioning and non-verbal cases, but people like me still get in. Yet whenever I had a problem that was Asperger's related, the best my school could think of was to either take pills or see a psychologist I couldn't afford and didn't need.
On the flip side, individual professors are willing to help. I know at least three of my professors have Asperger's, and academia does attract a disproportionate amount of neurodiverse people. They went through what your son and I had to go through, only with far less support. Trust me, they do not want to see someone held back because of this.
Virtually all professors are curious about Asperger's these days, because they are seeing more and more kids like your son in their classes.
I would encourage your son to go back to school and talk to his professors about it. Many are willing to help.