rtnetlink: Add VF config code to rtnetlink

Add code to allow rtnetlink clients to query and set VF information through
the PF driver.
Signed-off-by: Mitch Williams <mitch.a.williams@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>