He doesn't have the power to control machinery, he's just a human, not a mutant or anything. The onboard systems of the armor are controlled by Tony Stark's brain patterns, read from a cybernetic interface in his helmet. Sophisticated computers with an artificially intelligent operating system of Stark's own design provide tactical information as well as constant feedback on the suit's status, using internal and external sensors.
its the way he made his suits. its not mind control its just that he is a genies.
