ATLANTA — Eric Berry returned an interception for a touchdown, and then brought back another pick for a 2-point conversion that gave the Kansas City Chiefs an improbable 29-28 victory over the Atlanta Falcons on Sunday. The Falcons, rallying from a 27-16 deficit, went ahead 28-27 on Matt Ryan’s 5-yard touchdown pass to Aldrick Robinson with 4:32 remaining. Atlanta decided to go for 2, looking to stretch the margin to a field goal.