KANSAS CITY, Mo. (AP) — Patrick Mahomes looked up at the scoreboard late in the third quarter and was stunned to see the Kansas City Chiefs had taken a 31-0 lead over the AFC West rival Oakland Raiders. “I felt like we’d only scored a couple of times,” he said. That’s because the Chiefs’ high-powered offense didn’t need to do a whole lot Sunday. Their defense and the inept Raiders took care of…