IB/mlx5: Improve query port for representor port

IB/mlx5: Improve query port for representor port

Improve query port functionality for representor port as below.

1. RoCE Qkey violation counters are not applicable for representor port.
2. Avoid setting gid_tbl_len twice for representor port.
3. Avoid setting ip_gids and IB_PORT_CM_SUP property for representor port
   as GID table is empty and CM support is not present in representor
   mode.

Link: https://lore.kernel.org/r/20210203130133.4057329-4-leon@kernel.org
Signed-off-by: Parav Pandit <parav@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>