RDMA/hns: Support multi hop addressing for PBL in hip08

The block base address in the MR can be retrieved by the block number
which is calculated with the VA in the SGE and MTPT. In hip08, the PBL
supports multi hop addressing to retrieve the block base address by
the block number.

This patch is to add the interfaces in the MR to support multi hop
addressing for the PBL.

Signed-off-by: Shaobo Xu <xushaobo2@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>