VFs by default are able to see all tagged traffic regardless of trust
and VLAN filters. Based on legacy devices (i.e. ixgbe, i40e), customers
expect VFs to receive all VLAN tagged traffic with a matching
destination MAC.

Add an ethtool private flag 'vf-vlan-pruning' and set the default to
off so VFs will receive all VLAN traffic directed towards them. When
the flag is turned on, VF will only be able to receive untagged
traffic or traffic with VLAN tags it has created interfaces for.

Also, the flag cannot be changed while any VFs are allocated. This was
done to simplify the implementation. So, if this flag is needed, then
the PF admin must enable it. If the user tries to enable the flag while
VFs are active, then print an unsupported message with the
vf-vlan-pruning flag included. In case multiple flags were specified, this
makes it clear to the user which flag failed.
Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Tested-by: Gurucharan G <gurucharanx.g@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>