sfc: insert catch-all filters for encapsulated traffic

8000 series adapters support filtering VXLAN, NVGRE and GENEVE traffic
 based on inner fields, and when the NIC recognises such traffic, it
 does not match unencapsulated traffic filters any more.  So add catch-
 all filters for encapsulated traffic on supporting platforms.
Although recognition of VXLAN and GENEVE is based on UDP ports, and thus
 will not occur until the driver (on the primary PF) notifies the
 firmware of UDP ports to use, NVGRE will always be recognised, hence
 without this patch 8000 series adapters will drop all NVGRE traffic.

Partly based on patches by Jon Cooper <jcooper@solarflare.com>.

Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>