By Denny Dyroff, Entertainment Editor, The Times Phillip Phillips Fans of “American Idol” and “One Tree Hill” — take notice. On August 28, the Parx Casino’s Xcite Center will host a special twin-bill featuring co-headliners Phillip Phillips (“American Idol” winner) and Gavin DeGraw (who wrote the theme song for “One Tree Hill”). Doors for the show will open at 6 p.m. ...