common/iavf: support VLAN filtering

common/iavf: support VLAN filtering

In order to support enable/disable VLAN filtering the VF has to
negotiate the capability via VIRTCHNL_OP_GET_OFFLOAD_VLAN_V2. If
VIRTCHNL_VLAN_TOGGLE is allowed for the VLAN filtering capabilities,
then there needs to be a method to allow this. Make the necessary
changes to support this.

Also, since the virtchnl_vlan_offload message has the desired format,
change the structure name to virtchnl_vlan_setting so it can be used for
VIRTCHNL_OP_ENABLE_VLAN_FILTERING_V2 and
VIRTCHNL_OP_DISABLE_VLAN_FILTERING_V2.

Signed-off-by: Brett Creeley <brett.creeley@intel.com>
Signed-off-by: Haiyue Wang <haiyue.wang@intel.com>
Acked-by: Beilei Xing <beilei.xing@intel.com>