tg3: Use new VLAN code

This patch pivots the tg3 driver to the new VLAN infrastructure.
All references to vlgrp have been removed.  The driver still attempts to
disable VLAN tag stripping if CONFIG_VLAN_8021Q or
CONFIG_VLAN_8021Q_MODULE is not defined.

Signed-off-by: Matt Carlson <mcarlson@broadcom.com>
Reviewed-by: Michael Chan <mchan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>