If it is not supported we simply disable the feature.

For the feature to work we need firmware filter support for
OUTER_VID + LOC_MAC and for OUTER_VID + LOC_MAC_IG.
The low-latency firmware can match on OUTER_VID + LOC_MAC but not on
OUTER_VID + LOC_MAC_IG.
For the capture packet firmware it is the other way around.
Only the full-feature variant can match on both combinations.

Incorporates a fix by Andrew Rybchenko <Andrew.Rybchenko@oktetlabs.ru>
in the net_dev->[hw_]features handling.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>