Coulf be release bearing. Not simple to fix as you need to get engine and box apart. If you do, change clutch plates, bearing, fork and rear crank oil seal.
You can live with it mind.
If noise occurs in neutral then the bearing isnt making contact then it may not be the bearing but perhaps fork or bearing housing coming apart. Bearing only spins when clutch engaged. So could be plate breaking up or something? Either way, new clutch everything will sort.....