The Post’s Erich Richter makes his picks for Saturday’s  NFL  Divisional Round . SATURDAY Bills +1.5 over BRONCOS I’ll take the best quarterback in the NFL that has an elite offensive line and a top-five running back this weekend. Buffalo’s defense is a concern, and they are far from a perfect team, but the Broncos could get back Ed Oliver this weekend, which would be an obvious boon for them. Even without him for most of the season, the Bills average 5.3 yards per play, which is a below-