RDMA/hns: Modify the pbl ba page size for hip08

Modify the pbl ba page size to 16K for in order to support 4G MR size.

Signed-off-by: Wei Hu (Xavier) <xavier.huwei@huawei.com>
Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>