Merge branch 'DSA-tag_8021q-cleanup'

Vladimir Oltean says:

====================
DSA tag_8021q cleanup

This small series tries to consolidate the VLAN handling in DSA a little
bit. It reworks tag_8021q to be minimally invasive to the dsa_switch_ops
structure. This makes the rest of the code a bit easier to follow.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>