When reheating coated chicken, I find laying the pieces out on a flat cookie sheet (uncovered) in the oven on bake at 250° - 300° for roughly 30 mins, seems to do the trick to crisp up the coating, while not drying out the chicken itself.
I recommend experimenting with the temp setting and bake time, as all stoves are different, but I do think you'll be happy with the results.