IB/core: Add HDR speed enum

Add high data rate speed to the ib_port_speed enumeration.

Signed-off-by: Noa Osherovich <noaos@mellanox.com>
Signed-off-by: Eran Ben Elisha <eranbe@mellanox.com>
Signed-off-by: Leon Romanovsky <leon@kernel.org>
Signed-off-by: Doug Ledford <dledford@redhat.com>