common/mlx5: mark internal symbols

common/mlx5: mark internal symbols

Move mlx5 symbols in the map file to the INTERNAL section and add
__internal tags to their definitions.
Those symbols were exported in 20.02 and now (20.05) they are removed.
Avoid ABI comparison issues between 20.05/20.08 and 20.02 by adding the
suppress_file directive to libabigail.abignore file. This directive will
prevent loading mlx5 common symbols and no comparison will be performed.

In addition move symbols from the EXPERIMENTAL section to the INTERNAL
section.

Fixes: 7b4f1e6bd367 ("common/mlx5: introduce common library")
Signed-off-by: Ophir Munk <ophirmu@mellanox.com>
Acked-by: Matan Azrad <matan@mellanox.com>