VLAN tag is L2 construct, move VLAN code out from configuring IP.
Rearrange and rename the APIs to make it consistent.
Replace ENOSYS with EPERM.
Signed-off-by: NJitendra Bhivare <jitendra.bhivare@broadcom.com>
Reviewed-by: NHannes Reinecke <hare@suse.com>
Signed-off-by: NMartin K. Petersen <martin.petersen@oracle.com>