Ty Largo, one of the best-known marketing and public relations reps for Valley restaurants and bars, has died at age 40. The stunning announcement was made on social media this afternoon by Awe Collective, the Tempe-based agency he created. Largo passed away after ‘‘a private battle with his health,’’ it said. Largo and Awe Collective have provided marketing services for a who’s who of the Valley culinary world, including more than 100 restaurants, as well as other businesses. Plans for a celebration of life are pending.