Artificial intelligence chipmaker Cerebras Systems said on Friday that it's withdrawing plans for an IPO, days after raising over $1 billion in a fundraising round.In a filing with the SEC, Cerebras said it does not intend to conduct a proposed offering "at this time," but didn't provide a reason. A spokesperson told CNBC on Friday that the company still hopes to go public as soon as possible.Cerebras filed for an IPO just over a year ago, as it was ramping up to take on Nvidia in an effort to c...