PETERSBURG, Va. The mother of a Petersburg fifth grader who is on the autism spectrum is calling for criminal charges after she says five students attacked her son on a school bus Monday afternoon.Keonya Toran says she first learned something was wrong when her three elementary-age children came home Monday crying. Her son told her he had been beaten up."He came in, he was crying really bad and he says, 'They beat me up, they beat me up,'" Toran…