Dunno what data you want - all the far right groups were campaigning for Leave, there were loads of shots of known BNP / NF / Britain First / EDL / etc members on street stalls and the like campaigning for leave.
The organized far right may have voted Leave; it doesn't follow that all or even most racists did likewise.
Tbh, I suspect that they did. But I also think the connection between Leave and racism has been over-emphasized as part of the media's campaign to denigrate--and if possible ignore or reverse--the referendum result.