I might be wrong about the lack of OpenCL support.I doubt there is OpenCL access to these cards so you'll have to install CUDA then compile ethminer with CUDA support.
Note that I haven't purchased one yet, but I'm fairly certain this will be the case.
What is the ethminer command line you're attempting to use on this card?
The HP driver listed in this thread clearly states OpenCL.
https://support.hpe.com/hpsc/swd/pu...740c61e3f9724e678408d0060a&swEnvOid=4231#tab1