By Susan Heavey and James Oliphant WASHINGTON (Reuters) - Republican Donald Trump took steps to steer his White House campaign back into favor with his party on Friday with reported plans to endorse U.S. House of Representatives Speaker Paul Ryan after expressing coolness toward him earlier this week. Fox News and CNN said Trump would endorse Ryan, the top U.S. elected Republican, in his re-election bid at a rally in Green Bay, Wisconsin, which is Ryan's home state. Ryan had no plans to attend the event, in a sign of lingering frictions between them.