Have you checked your toe-in yet? This can have an effect on how your camber is set.
Just installing the disc brakes should not have effected alignment, but if something was bent, or they somehow installed some oddball knuckles on there, then I suppose that could cause this to happen.
Wear on the outside of the tire is, unfortunately, very common on Broncos. Factory specs call for as much as 1° positive camber (maybe even a little more) and with that added to the toe-in, you get the tires spending too much time rolling around on their outer edges. Keeping camber to a minimum (say, no more than 1/2°) can help. Keeping toe-in to the minimum effective amount helps too, but too little and you can have other steering issues, so you have to play with it on every rig to see what makes it happy. About 1/8" toe-in is a good place to start.
You should measure yours just to find out where you stand. But like I said, knowing what your full alignment settings currently are is an invaluable tool for your future uses.
Regarding your camber though, as was mentioned, there are two common methods of adjustment. The upper ball-joint eccentric sleeves, and camber shims that go between the spindle and the knuckle.
If you have the GM brake system, you still have the stock 6-bolt spindles that Ford used on drum brake Broncos. If yours has been converted to a Ford disc brake setup though, you'll have the 5-bolt spindles with the larger flange. Harder to find shims for those, but I think they're still out there.
Good luck.
Paul