By Jonathan Stempel (Reuters) – HP Inc’s stock soared to a record high on Thursday after Warren Buffett’s Berkshire Hathaway Inc revealed it had taken an 11.4% stake valued at about $4.2 billion in the maker of personal computers and printers. Berkshire said on Wednesday night it owned nearly 121 million HP shares, including 11.1 million purchased this week. Shares of HP were up $5.28, or 15.1%, at $40.19 in early trading on Thursday, after earlier reaching a record $40.50. Separated in 2015 from the former Hewlett-Packard, HP is a traditional technology stock that has benefited from increased…