Raja Koduri, CTO of the graphics product group at AMD, has left the company to take an unspecified position at Apple, according to a new report. Citing people familiar with Apple’s plans, the Wall Street Journal reports that Koduri started work this week, and will help the iPod maker design multifunction chips for use in the iPhone, iPod touch, and other yet-unannounced mobile devices. The report suggests the chips may offer drastic reductions…