I think once the steerer tube is bent, the fork is pretty much toast.......
I don't think any frame builder would suggest bending it back straight, and replacement of the steerer tube might be cost prohibitive as a replacement fork might cost just as much.....or less...
BTW, bending a steerer tube in a crash might mean there's more damage than what's easily seen as it would have taken a lot of impact force to make it happen. Make sure to check the top and down tunes for any bending or buckling......