RDMA/hns: Support query information of functions from FW

Add a new type of command to query mac id of functions from the firmware,
it is used to select the template of congestion algorithm. More info will
be supported in the future.

Link: https://lore.kernel.org/r/1616679236-7795-2-git-send-email-liweihang@huawei.com


Signed-off-by: Wei Xu <xuwei5@hisilicon.com>
Signed-off-by: Shengming Shu <shushengming1@huawei.com>
Signed-off-by: Weihang Li <liweihang@huawei.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>