Sean Kingston is trying to expand his portfolio beyond the music world and we ain’t mad at him! Sean is reportedly starting his own professional boxing league for rappers, according to The Blast.He’s teaming up with Triple The Mogul, a famed hip-hop agent, to create the Professional Rapper Boxing League (PRBL) and they reportedly already have several rappers on board who are willing to fight once the league is established.Word on the street is that even Soulja Boy is considering joining the