common/sfc_efx/base: add MAE match field VNET ID for tunnels
Add MCDI-compatible enumeration for this field and
provide necessary mappings for it to be inserted
directly into mask-value pairs buffer.
VNET_ID can be used to serve the following match fields:
rte_flow_item_vxlan.vni, rte_flow_item_geneve.vni,
rte_flow_item_nvgre.tni
Signed-off-by: Ivan Malov <ivan.malov@oktetlabs.ru> Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com> Reviewed-by: Andy Moreton <amoreton@xilinx.com>