Your game doesn't need to have antialias settings as they are included in graphics drivers interface such as ATI Catalyst.
It's very bad practice to ask your users to change driver settings for something you should be doing in-game. Not only can you not switch on the fly, but if every game did that, you'd be going in and out of driver settings several times a day as you switched from one game to another.
Personally I don't like anti-aliasing when I'm playing, but if a game can't give me an option in-game, I'm not going to fiddle with driver settings to force it. It's a programmer's job.