RDMA/mlx5: Attach ndescs to mlx5_ib_mkey

Generalize the use of ndescs by adding it to mlx5_ib_mkey.

Signed-off-by: Aharon Landau <aharonl@nvidia.com>
Reviewed-by: Shay Drory <shayd@nvidia.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>

RDMA/mlx5: Cleanup DEVX initialization flow

Move DEVX initialization and cleanup flows to the devx.c instead of having
almost empty functions in main.c

Link: https://lore.kernel.org/r/20200702081809.423482-6-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>

RDMA/mlx5: Separate flow steering logic from main.c

Move flow steering logic to be in separate file and rename flow.c to be
fs.c because it is better describe the content.

Link: https://lore.kernel.org/r/20200702081809.423482-5-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>