net: dsa: bcm_sf2: Add support for matching VLAN TCI

Update relevant code paths to support the programming and matching of
VLAN TCI, this is the only member of the ethtool_flow_ext that we can
match, the switch does not permit matching the VLAN Ethernet Type field.

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>