This article makes it sound like a grinder is not necessary:
Mix into baked goods. You can use freeze-dried fruit inside of baked goods where you’d otherwise think about traditionally dried or even fresh fruit. Again, the bonus: No added moisture to mess with your batter. Plus, they’ll plump a little and be pleasantly chewy after baking. So go ahead and stir them into your favorite muffin, scone, oatmeal cookie or quick bread recipe.