Definitely boil it, but only for long enough to really dissolve it - unless you have mold growth, maple syrup doesn't really spoil or grow harmful stuff.
Be aware that using priming sugar for flavor will, at best, give you a hint of the flavor you are looking for - maple syrup is no exception to this.
If you want maple flavor, you need a large amount of the lowest grade syrup you can find (grade A table syrup ferments almost completely away with little flavor contribution beyond a "woody" flavor), and that needs to go into your boil or fermentor.