I don't believe there is, given the amount of work that would be involved in creating one and the relatively small pool of people that would even be interested in such a thing, given the limitations of mining for vanity addresses (ie. limited length vs. ridiculous difficulty). Miners aren't exactly cheap... and there really isn't much in the way of rewards for generating vanity addresses... look at the existing website/pool/service that has been setup... they're certainly not making 12.5BTC for "hitting the jackpot" like you get when attempting to mine coins.
Hardware miners are designed/built to work on mining coins themselves, not generating addresses. Granted it is a very similar thing, generating and comparing hashes etc. so I suppose it would be possible to modify an existing miner, assuming you can modify the firmware/OS onboard the miner... and you knew how to do that
I would think the real question is not if you could do it... but why would you do it??
