Justin Timberlake used to have his name on a title sponsorship of a PGA Tour stop in Las Vegas. He’s also a regular on the celebrity pro-am circuit. Now the musician and actor has signed on as investor in a par-3 golf course, according to thestate.com. Timberlake is involved with 8AM Golf, which is part of Nicklaus Companies. 8AM recently bought a 35-percent stake in 3’s Greenville Golf in Greenville, South Carolina. Originally called Crosswinds, the course is owned by Davis Sezna, who bought the 30-year-old course four years ago. The name fits better with the par-3 layout but also…