IB/mlx5: Fix DEVX support for MLX5_CMD_OP_INIT2INIT_QP command

IB/mlx5: Fix DEVX support for MLX5_CMD_OP_INIT2INIT_QP command

The commit citied in the Fixes line wasn't complete and solved
only part of the problems. Update the mlx5_ib to properly support
MLX5_CMD_OP_INIT2INIT_QP command in the DEVX, that is required when
modify the QP tx_port_affinity.

Fixes: 819f7427bafd ("RDMA/mlx5: Add init2init as a modify command")
Link: https://lore.kernel.org/r/20200527135703.482501-1-leon@kernel.org
Signed-off-by: Mark Zhang <markz@mellanox.com>
Reviewed-by: Maor Gottlieb <maorg@mellanox.com>
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>