View image | gettyimages.com   The Philadelphia Eagles have reportedly traded third-string quarterback Matt Barkley to the Arizona Cardinals for a conditional seventh-round draft pick. The Eagles will earn a sixth-round pick if Barkley is on the Cardinals’ roster for at least six games in the 2015 season, per NFL Network’s insider Ian Rapoport. Barkley, who was unimpressive throughout training camp and the preseason, ends his three-year Eagles career…