RDMA/hns: Add interfaces to get pf capabilities from firmware

pf capabilities are set by default for hip08 previously which should
depends on different types of hardware. So add new interfaces to get them
from firmware.

Link: https://lore.kernel.org/r/1578738761-3176-3-git-send-email-liweihang@huawei.com


Signed-off-by: Lijun Ou <oulijun@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>