O2 has announced its data plan pricing for the iPhone 4 in the U.K., while removing its unlimited data options. O2’s new plans scale the amount of data along with the number of voice minutes, ranging from 100 minutes and 500MB of data for £25 a month on a two-year contract to unlimited minutes and 1GB of data for £65 per month with an 18-month agreement. All of O2’s new plans also include unlimited use of the company’s U.K. Wi-Fi…