common/mlx5: remove DevX dependency on Verbs and DV

common/mlx5: remove DevX dependency on Verbs and DV

File mlx5_devx_cmds.c should contain pure DevX calls. It must be OS
agnostic and not include any references to ibv or dv structs (defined in
ibverbs and rdma-core linux libraries).  This commit replaces all ibv
and dv references with 'void *'.  Specifically, the following struct
were replaced:
1. struct ibv_context *
2. struct ibv_qp *
3. struct mlx5dv_devx_cmd_comp *

Signed-off-by: Ophir Munk <ophirmu@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>