i40e: Fix VF disable behavior to block all traffic

Currently, if a VF is disabled using the
'ip link set dev $ETHX vf $VF_NUM state disable' command, the VF is still
able to receive traffic.

Fix the behavior of the 'ip link set dev $ETHX vf $VF_NUM state disable'
to completely shutdown the VF's queues making it entirely disabled and
not able to receive or send any traffic.

Modify the behavior of the 'ip link set $ETHX vf $VF_NUM state enable'
command to make a VF do reinitialization bringing the queues back up.

Co-developed-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Signed-off-by: Aleksandr Loktionov <aleksandr.loktionov@intel.com>
Reviewed-by: Jan Sokolowski <jan.sokolowski@intel.com>
Reviewed-by: Wojciech Drewek <wojciech.drewek@intel.com>
Reviewed-by: Przemek Kitszel <przemyslaw.kitszel@intel.com>
Signed-off-by: Andrii Staikov <andrii.staikov@intel.com>
Tested-by: Rafal Romanowski <rafal.romanowski@intel.com>
Signed-off-by: Tony Nguyen <anthony.l.nguyen@intel.com>