net: mscc: ocelot: write full VLAN TCI in the injection header

The VLAN TCI contains more than the VLAN ID, it also has the VLAN PCP
and Drop Eligibility Indicator.

If the ocelot driver is going to write the VLAN header inside the DSA
tag, it could just as well write the entire TCI.

Signed-off-by: Vladimir Oltean <vladimir.oltean@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>