Add the Hyper-V _DSM command set to the white list of NVDIMM command
sets.

This command set is documented at http://www.uefi.org/RFIC_LIST
(see "Virtual NVDIMM 0x1901").
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>