By Zaheer Kachwala (Reuters) -Videogame developer Electronic Arts has agreed to sell itself to a group of private investors in a deal that values the maker of "Battlefield" and "Madden NFL" at $55 billion, which if completed would be the largest leveraged buyout in history. Saudi Arabia's Public Investment Fund, Jared Kushner's Affinity Partners and private equity firm Silver Lake came together to buy the popular videogame maker with a combination of$36 billion in cash, equity already held by PIF, and $ ...