i40e: limit sriov to partition 1 of NPAR configurations

Make sure we only allow SR/IOV on the master PF of a port in multifunction
mode.  This should be the case anyway based on the num_vfs configured in
the NVM, but this will help make sure there's no question.  If we're not
in multifunction mode the partition_id will always be 1.

Change-ID: I8b2592366fe6782f15301bde2ebd1d4da240109d
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Tested-by: Jim Young <james.m.young@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>