bnxt_en: Add hardware NTUPLE filter for encapsulated packets.

If skb_flow_dissect_flow_keys() returns with the encapsulation flag
set, pass the information to the firmware to setup the NTUPLE filter
accordingly.

Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>