A powerhouse black supporting player and occasional lead, Paul Winfield gained international recognition and a Best Actor Oscar nomination opposite Cicely Tyson in Martin Ritt's "Sounder" (1972).Winfield has worked consistently in theater, film and TV, offering one of his finest performances in the latter: as Martin Luther King Jr. in the NBC miniseries "King" (1978) He also scored on the big screen as Gabriel Grimes, the semi-autobiographical hero in the adaptation of James Baldwin's novel "Go Tell It On the Mountain" (1984) and as the college chancellor willing to sing Negro spirituals to