I don't think you will be able to get shavings from chips. They are just too small. I doubt it would work in the FP anyway. Chips are inexpensive though so buy a bag and give it a shot. I would freeze them first so that there is less chance of them melting, which I think would be a big possibility using the FP.
I have a hand held food chopper where the motor is on top and I used it to "grate" chocolate chips. It came out in small chunks slightly bigger than sprinkles. It worked for the recipe I was making at the time but didn't really "shave" it. If you want curly-q's I'd go with the veggie peeler on a candy bar or other blocks of chocolate.