The only films I can think of are Milton Glaser: To Inform and Delight and Design & Thinking.
Google turns up this link on Creativebloq.com.
And this is probably the best film every designer should watch. (John Cleese on Creativity)
As far as I know all films about design are classified as documentaries. If they aren't documentaries, they are scripted... and therefore not informative, but meant to be entertaining. Perhaps you mean not "biographies"?
If you are thinking more along hollywood releases, there are films such as Crazy People, or Syrup but these seem to be more about marketing and advertising than actual design to me. And, of course, being scripted they aren't really that realistic in many areas.