i40e: Restrict VF poll mode to only single function mode devices

i40e: Restrict VF poll mode to only single function mode devices

Orabug: 23176970

The VFs can request their queues to be set up into polling mode, rather
than interrupt mode, which works well for supporting things like DPDK,
but this should not be available when working in an multi-function
support device.

Change-ID: Id36792e4e7422db8f2033336507211f68f14ff6f
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
(cherry picked from commit 14c5f5d264c3ee28e8ec9fd4dffb29f5d1ea1d02)
Signed-off-by: Brian Maly <brian.maly@oracle.com>