net/mlx5: add shared device context config structure

net/mlx5: add shared device context config structure

Add configuration structure for shared device context. This structure
contains all configurations coming from devargs which oriented to
device. It is a field of shared device context (SH) structure, and is
updated once in mlx5_alloc_shared_dev_ctx() function.
This structure cannot be changed when probing again, so add function to
prevent it. The mlx5_probe_again_args_validate() function creates a
temporary IB context configure structure according to new devargs
attached in probing again, then checks the match between the temporary
structure and the existing IB context configure structure.

Signed-off-by: Michael Baum <michaelba@nvidia.com>
Acked-by: Matan Azrad <matan@nvidia.com>