net/mlx5: Set software owner ID during init HCA

Generate a unique 128bit identifier for each host and pass that value to
firmware in the INIT_HCA command if it reports the sw_owner_id
capability. Each device bound to the mlx5_core driver will have the same
software owner ID.

In subsequent patches mlx5_core devices will be bound via a new VPort
command so that they can operate together under a single InfiniBand
device. Only devices that have the same software owner ID can be bound,
to prevent traffic intended for one host arriving at another.

The INIT_HCA command length was expanded by 128 bits. The command
length is provided as an input FW commands. Older FW does not have a
problem receiving this command in the new longer form.

Signed-off-by: Daniel Jurgens <danielj@mellanox.com>
Reviewed-by: Parav Pandit <parav@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>