acenic: do vlan cleanup

- unify vlan and nonvlan rx path
- kill ap->vlgrp and ace_vlan_rx_register
- enable vlan hw accel always (kill vlan ifdefs)

Signed-off-by: Jiri Pirko <jpirko@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>