By JON CARAMANICA There was talk of kokolets all Sunday night at Irving Plaza. D'Banj, the Nigerian pop star who was headlining the show, boasted, "I have too many kokolets around the world." Later on he wondered, "Can I get two kokolets that can dance better than my dancers?" If it seemed like D'Banj, one of the quickest-rising stars in Africa, has a one-track mind - kokolets, in his lingo, are beautiful women - that wasn't far from the truth. As a style, his was as monomaniacal in focus as Miami bass, one lusty come-on after the next. He is at the forefront of an emergent style loosely called Afrobeats by some, a mélange of hip-hop, R&B and other traditionally urban sounds with elements that hark back to older African styles. In practice on Sunday all that meant was that D'Banj, backed by