IT'S ALL RELATIVE: In his latest film, Crooklyn, director Spike Lee pays homage to two swinging '70s familieshis own and, believe it or not, the Partridges. Written by Spike, sister Joie, and brother Cinque, the film includes a scene in which the Brooklyn brood battles over what to watch on TV. ''My family was the Partridge Family bloc,'' says Lee, who admits that David Cassidy's pleas to ''Come On, Get Happy'' left him coldas they did Crooklyn's oldest boy. ''I hated the show,'' he says. ''It was on at the same time as the Knicks, but I always got outvoted.''