Optimize the SRQ's WQE buffer parameters calculating process to make the
codes more readable by using new functions about multi-hop addressing to
calculating capabilities of SRQ.

Link: https://lore.kernel.org/r/1588071823-40200-6-git-send-email-liweihang@huawei.comSigned-off-by: NXi Wang <wangxi11@huawei.com>
Signed-off-by: NWeihang Li <liweihang@huawei.com>
Signed-off-by: NJason Gunthorpe <jgg@mellanox.com>