net: sh_eth: add support for VLAN tag filtering

Some controllers have TSU. It can register one VLAN tag, and it can
filter other VLAN tag by hardware.
If vlan_rx_add_vid() is called twice or more, the driver will disable
the filtering.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: David S. Miller <davem@davemloft.net>