Nov 12 (Reuters) - Nvidia CEO Jensen Huang stepped down on Thursday after revelations of extramarital affairs, including one involving a suspected Chinese spy, plunged the chipmaker into crisis and sent shockwaves across an AI industry he helped bankroll. By Aditya Soni and Anhata Rooprai Nov 12 (Reuters) - Nvidia CEO Jensen Huang stepped down on Thursday after revelations of extramarital affairs, including one involving a suspected Chinese.