AMD has announced that it has hired Jim Keller away from Apple. Keller, who joined Apple as part of its acquisition of PA Semi, was a director in the platform architecture group and was focused on mobile products, playing a key role in the development of the A4 and A5 chip families. At AMD, Keller will serve as corporate vice president and chief architect of AMD’s microprocessor cores, and will report to CTO and senior vice president of technology…