A mushroom is a sexual organ so no I don't think anything like it would evolve to become anything like a brain, its way to temporary. Fungi can create enourmess mycelial networks but as far as them being what I consider intelligent, I would say no. By intelligent I mean self aware etc. Many animals are capable of this however and I am sure other forms of life could evolve higher levels of intelligence as well. Just because mushrooms contain compounds that happen to get us really high doesn't have to mean that they make those compounds for us or to communicate with us.