NORMAN (AP) — Iowa State coach Matt Campbell saw an opportunity to seize a win that would boost the Cyclones’ chances of reaching the Big 12 title game, so he put everything on quarterback Brock Purdy. His gamble failed. Parnell Motley intercepted Purdy’s two-point conversion pass with 24 seconds left, and No. 9 Oklahoma held off Iowa State 42-41 on Saturday night. And now, Iowa State’s…