net/mlx5: map UAR address around huge pages

net/mlx5: map UAR address around huge pages

Reserving the memory space for the UAR near huge pages helps to
**reduce** the cases where the secondary process cannot start. Those
pages being physical pages they must be mapped at the same virtual
address as in the primary process to have a
working secondary process.

As this remap is almost the latest being done by the processes
(libraries, heaps, stacks are already loaded), similar to huge pages,
there is **no guarantee** this mechanism will always work.

Signed-off-by: Xueming Li <xuemingl@mellanox.com>
Acked-by: Nelio Laranjeiro <nelio.laranjeiro@6wind.com>