“Known for his roles in “Lost” and “Oz,” Adewale Akinnuoye-Agbaje is now telling a far more important story — his own. The actor is making a film entitled “Farming” about the practice followed by many Nigerian parents in 1960s and ’70s Britain of having children informally fostered. Akinnuoye-Agbaje, 44, was raised in such a situation, …