Soul diva Mary J. Blige has signed on to play warbler Nina Simone in a biopic of the legendary singer.Pic — titled “Nina” — focuses on Simone’s relationship later in life with her assistant Clifton Henderson, played by David Oyelowo (“The Last King of Scotland”). Script is penned and directed by “The Brave One” scribe Cynthia Mort. William Morris Endeavor’s global finance and distribution group will handle North American rights while Ealing Studios will finance, produce and sell internationally. The $10 million biopic will begin shooting in France in September. Simone — nicknamed “the High Priestess of Soul” — is best known for tunes “My Baby Just Cares for Me,” “I Put A Spell on You.” She was also an avid civil right activist.