RDMA/opa_vnic: Delete driver version

The default version provided by "ethtool -i" it the correct way
to identify Driver version. There is no need to overwrite it.

Link: https://lore.kernel.org/r/20200220071239.231800-3-leon@kernel.org


Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Reviewed-by: Dennis Dalessandro <dennis.dalessandro@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>