[TIPC]: Add support for Ethernet VLANs

This patch enhances TIPC's Ethernet support to include VLAN interfaces.

Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Per Liden <per.liden@ericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>