Speaking with reporters, O2 U.K. CEO Ronan Dunne revealed that the company has sold two million iPhones since the carrier began offering the device in November 2007. Reuters reports that Dunne also said O2 still enjoys a boost from being the first carrier in the region to offer the iPhone, despite the fact that it is now available on rival carriers Orange and Vodafone. “It will take a long time before that goes away,” Dunne said. O2 announced…