mlxsw: make mlxsw_config_profile const

Make these structures const as they only stored in the profile field of
a mlxsw_driver structure, which is of type const.
Done using Coccinelle.

Signed-off-by: Bhumika Goyal <bhumirks@gmail.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>