Kim Dickens will making her long-awaited return as Madison Clark in the second half of “Fear of the Walking Dead” Season 7 — and as a series regular after that. The “Walking Dead” spinoff series has been renewed for Season 8 at AMC, the cable channel said Monday, with Dickens set to make her comeback as the presumed-dead Madison (who hasn’t been seen since Season 5) in the back half of Season 7, which debuts Sunday, April 17.