Fix Rx checksum status for tunnel frames as seen by hardware.
Current code does not handle cases for tunnel frames correctly.
Fixes: 7ec39d8c524b ("net/bnxt: update status of Rx IP/L4 CKSUM")
Cc: stable@dpdk.org
Signed-off-by: Ajit Khaparde <ajit.khaparde@broadcom.com>