IB/mlx5: Set the default active rate and width to QDR and 4X

IB/mlx5: Set the default active rate and width to QDR and 4X

Before commit f1b65df5a232 ("IB/mlx5: Add support for active_width and
active_speed in RoCE"), the mlx5_ib driver set the default active_width
and active_speed to IB_WIDTH_4X and IB_SPEED_QDR.

When the RoCE port is down, the RoCE port does not negotiate the active
width with the remote side, causing the active width to be zero. When
running userspace ibstat to view the port status, ibstat will panic as it
reads an invalid width from sys file.

This patch restores the original behavior.

Fixes: f1b65df5a232 ("IB/mlx5: Add support for active_width and active_speed in RoCE").
Signed-off-by: Honggang Li <honli@redhat.com>
Reviewed-by: Hal Rosenstock <hal@mellanox.com>
Reviewed-by: Noa Osherovich <noaos@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>