DETROIT — The Lions finally raised a banner at Ford Field this week. Now it’s time to go validate it. Or, as safety C.J. Gardner-Johnson put it Sunday, “We got two more banners to hang.” First things first, though: There are some ghosts here that still need to be chased away. And one of them is coming back to his old haunt next weekend for the first-ever playoff game in this stadium, as the Lions host Matthew Stafford and the Los Angeles Rams in their NFC wild-card opener. Get ready to boo, Detroit. This is the moment you’ve been waiting for, isn’t it? Sunday was another moment, of course. And…