By Yaron Weitzman
FOX Sports NBA Writer
One of the NBA’s most powerful figures is leaving his NBA job.
Michael Rubin — the billionaire known for having the ears of star athletes, league offices and team owners — is selling his 10% stake in Harris Blitzer Sports & Entertainment, the parent company of the Philadelphia 76ers and New Jersey Devils, he told FOX Sports in an interview this week.
Rubin, 49, has played a key role in the…