net/bnxt: support tunnel offload

net/bnxt: support tunnel offload

Add support for tunnel offload APIs. Specifically the following
are supported.
tunnel_decap_set, tunnel_match, tunnel_action_decap_release,
tunnel_item_release.

This provides support for VXLAN decap action where two flows
can indicate tunnel offload rule. The first flow indicates the
tunnel properties and second flow indicates the inner packet
structure. The templates are updated to support this
feature.

Signed-off-by: Kishore Padmanabha <kishore.padmanabha@broadcom.com>
Signed-off-by: Venkat Duvvuru <venkatkumar.duvvuru@broadcom.com>
Reviewed-by: Shahaji Bhosle <sbhosle@broadcom.com>
Acked-by: Ajit Khaparde <ajit.khaparde@broadcom.com>