Great idea if you want the maple syrup flavors in the bottles... For how much, I seem to recall that it's about 60% fermentable sugars. At most, no more than honey is (80%).
A quick check shows it's potential as 1.030, where honey is 1.035... About 65% fermentable sugars in it... So use that to figure out how much to use (by weight) to obtain your CO2 volume target.
I used 1.25x the white priming sugar weight for honey when priming with that. If my math is correct (not sure it is) you'll want to use about 1.55x the sugar weight in maple syrup... I would aim for the middle CO2 volumes for the brew. That way, if there's a bit more sugar the yeast can much, it won't be over carbonated.
BTW, I have a maple brown ale on deck. Planning on using a full pint of syrup (local make) in it once fermentation has slowed down... So probably about 3-4 weeks after the yeast gets pitched. I'll let it ride another couple of weeks from then, before going to bottle/keg... I'm starting to lean more towards kegging everything than even bottling part of batches.