What is ATTOcelebrity.kext?
ATTOCelerityFC8.kext is a driver for some ATTO fibre channel cards. They fit in some pre-"trash can" Mac Pros only.

ATTO explicitly lists all Mac compatible adapters here: Apple Solutions, but forgot to update the list for High Sierra.

There is no real doubt that the driver is genuine.

The ATTOCelebrity kext is some figment of imagination only ;-)