RDMA/nldev: Allow counter auto mode configration through RDMA netlink

Provide an option to enable/disable per-port counter auto mode through
RDMA netlink. Limit it to users with ADMIN capability only.

Signed-off-by: Mark Zhang <markz@mellanox.com>
Reviewed-by: Majd Dibbiny <majd@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>