The pvrdma_port_attr structure is ABI toward the hypervisor, changing it
breaks the ability to report the speed properly. Revert the change to u16.

Fixes: 376ceb31 ("RDMA: Fix link active_speed size")
Link: https://lore.kernel.org/r/20201102225437.26557-1-aditr@vmware.comReviewed-by: Vishnu Dasa <vdasa@vmware.com>
Signed-off-by: Adit Ranadive <aditr@vmware.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>