Two-time Tony winner Chita Rivera will be the center of attention at a star-studded gathering honoring the Broadway icon’s 80th birthday (which she celebrated in January 2013). Broadway Cares/Equity Fights AIDS will present Chita: A Legendary Celebration, an original piece directed by Graciela Daniele and written by Terrence McNally, on October 7 at the August Wilson Theatre. With credits like West Side Stor…