Disc Rotor Alignment Mavic Crosstrail
How much displacement are we talking about.  A mm or two?  

I've never heard of the wheel moving along the axle.  Is the 15QR skewer (the axle) tight?  There is a rotatable nut with numbers on the opposite side which you can adjust to move the final angle at which the skewer lever handle sits.

One thing I would try is to remove the caliper completely (two bolts to the fork) and see if the rim and or the rotor wobbles when turned.  Also check to see if the wheel itself is loose and moves "along the axle" or rattles / has loose play.  The front wheel on my Nerve AL 8.9 is centered, as far as I can tell.

It's possible that the caliper position changed during a crash.  There is slop in the two mounting bolts on purpose so that you can center the caliper pads onto the disk.  But before you try that, you should probably make sure the disks aren't warped as well.