net/sfc: support VLAN presence match in transfer rules

net/sfc: support VLAN presence match in transfer rules

Take into account VLAN presence fields in items ETH and VLAN.

Provided that the item ETH does not match on the EtherType,
the pattern behaviour will be as follows:

- ETH (mask->has_vlan = 0) | IPv4        = match both tagged and untagged;
- ETH (mask->has_vlan = 1) | IPv4        = match as per spec->has_vlan;
- ETH (mask->has_vlan = 0) | VLAN | IPv4 = match only tagged.

Similar logic applies to double tagging.

Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru>
Reviewed-by: Andrew Rybchenko <andrew.rybchenko@oktetlabs.ru>
Reviewed-by: Andy Moreton <amoreton@xilinx.com>