net/mlx5: Add ifc bits to support optional counters

Adding bth_opcode field and the relevant bits. This field will be used
to capture and count congestion notification packets (CNP).

Adding source_vhca_port support bit.
This field will be used to check the capability to use the
source_vhca_port as a match criteria in cases of dual port.

Signed-off-by: Aharon Landau <aharonl@nvidia.com>
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>