AT&T may be planning to charge iPhone users extra for FaceTime over Cellular capabilities, according to a new report. Citing a new alert that appears in iOS 6 beta 3 warning users that in order to enable FaceTime over cellular, they must contact AT&T, 9to5Mac reports that it appears AT&T is planning to charge extra for the feature, as they do for Personal Hotspot access. AT&T provided a statement for the report, which reads, “We’re…