net/mlx5: Add flow-steering commands for FPGA IPSec implementation

In order to add a context to the FPGA, we need to get both the software
transform context (which includes the keys, etc) and the
source/destination IPs (which are included in the steering
rule). Therefore, we register new set of firmware like commands for
the FPGA. Each time a rule is added, the steering core infrastructure
calls the FPGA command layer. If the rule is intended for the FPGA,
it combines the IPs information with the software transformation
context and creates the respective hardware transform.
Afterwards, it calls the standard steering command layer.

Signed-off-by: Aviad Yehezkel <aviadye@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>