I read it as entirely ambiguous. It turns on the meaning of “ends”: it could mean “terminates,” implying that Islam somehow defeats racism, or it could mean “has as its purpose or outcome,” indicating that racism leads to Islamic belief.
Neither interpretation makes much sense.
My guess would be, first, that it alludes to, and is meant to be a reminder of, something that has been or is being conveyed in another medium. I recognize that many billboards that seem cryptic to me are going to have meaning to people who watch television, whereas I sometimes can’t even guess what they’re advertising. Maybe it refers to print or broadcast messages that you haven’t seen or heard, or even to a line of scripture.
Second, I would speculate that the line is translated from another language that doesn’t have the same nearly opposite meanings of “ends”—or, if it has, the intent is clear, whereas in English it is not.
Do you know anyone in the Islamic community who could explain?