nfp: use PCI_DEVICE_ID_NETRONOME_NFP6000_VF for VFs instead

The PCI_DEVICE_ID_NETRONOME_NFP6000_VF is available for use and
should be used instead of the PCI_DEVICE_NFP6000VF. Meanwhile,
PCI_DEVICE_NFP6000VF PCI ID is removed for not being used.

Signed-off-by: Dirk van der Merwe <dirk.vandermerwe@netronome.com>
Signed-off-by: Fei Qin <fei.qin@corigine.com>
Signed-off-by: Simon Horman <simon.horman@corigine.com>
Signed-off-by: Jakub Kicinski <kuba@kernel.org>