net/mlx5: Introduce new TIR creation core API

Introducing new TIR creation core API which allows caller
to receive back from the call the full command outbox.

This comes as a preparation for the next patch that will
retrieve the TIR ICM address from the command outbox.

Signed-off-by: Ariel Levkovich <lariel@mellanox.com>
Reviewed-by: Eli Cohen <eli@mellanox.com>
Reviewed-by: Mark Bloch <markb@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Saeed Mahameed <saeedm@mellanox.com>