IB/hns: Delete the sqp_start from the structure hns_roce_caps

This patch deleted the sqp_start from the structure hns_roce_caps, and
modified the calculation of the qp number.

Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Salil Mehta <salil.mehta@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>