I think that it is useless to try to solve a TSP using ga, mainly because ga is so slow and unreliable compared to Optimization Toolbox solvers. If you want to see an approach to solving a TSP using ga, look at Custom Data Type Optimization Using the Genetic Algorithm.
But if you ignore my advice and insist on trying to use ga inappropriately to solve a TSP using exactly the algorithm described for intlinprog, then you need to create a function handle that gives the value of a tour; you cannot use a vector as intlinprog does to represent an objective function.
fun = @(x)dot(x,dist);
Please do not use this; you will not get a good solution, and it will take a long time.
Alan Weiss
MATLAB mathematical toolbox documentation