bnxt_en: Ignore src port field in decap filter nodes

The driver currently uses src port field (along with other fields) in the
decap tunnel key, while looking up and adding tunnel nodes. This leads to
redundant cfa_decap_filter_alloc() requests to the FW and flow-miss in the
flow engine. Fix this by ignoring the src port field in decap tunnel nodes.

Fixes: f484f678 ("bnxt_en: add hwrm FW cmds for cfa_encap_record and decap_filter")
Signed-off-by: Sriharsha Basavapatna <sriharsha.basavapatna@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>