RDMA/mlx5: Enable querying AH for XRC QP types

Address handle is set for connected QP types such as RC and UC, and thus
can also be queried.

Since XRC QP types INI and TGT are connected, it should be possible to
query their address handle as well.

Until now it was not the case, and although the firmware supported it, the
driver allowed querying the address handle only for RC and UC.

Hence, we enable it now for INI and TGT QPs as well.

Link: https://lore.kernel.org/r/20201115121425.139833-2-leon@kernel.org
Reviewed-by: Maor Gottlieb <maorg@nvidia.com>
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
Signed-off-by: Leon Romanovsky <leonro@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>