The extra time can really probably come into play and help you in exams, I can imagine that stress could make dyslexia worse and that some exam papers especially when poorly printed can be very difficult to read.
But a free computer?! meh... come on mun... you have access to all of that anyway for free in university itself which is only what.. 5 mins down the road?. Dont see how its fair to award such things to folk who have dyslexia.
Its akin to giving a free wheelchair to someone who can walk but requires a walking stick just for a little extra support. aka its overkill