After 4 years, I wouldn't say anything especially since he's not hogging it. It'll only lead to awkwardness. If it really bothers you, take them off your desk. But, as already mentioned, a handful of tic tacs every week in exchange for an otherwise good boss sounds like a pretty good deal.
Out of curiosity, do you remember if he asked you the very first time?
Communal candy on someone's desk is not uncommon, so while he should ask and not assume (especially as it's unwrapped), based on his behavior with his own snacks, he has different food boundaries. We all have our quirks. This is his.