RDMA/cma: Support IB service record resolution

RDMA/cma: Support IB service record resolution

Add new UCMA command and the corresponding CMA implementation. Userspace
can send this command to request service resolution based on service
name or ID.

On a successful resolution, one or multiple service records are
returned, the first one will be used as destination address by default.

Two new CM events are added and returned to caller accordingly:
  - RDMA_CM_EVENT_ADDRINFO_RESOLVED: Resolve succeeded;
  - RDMA_CM_EVENT_ADDRINFO_ERROR:  Resolve failed.

Internally two new CM states are added:
  - RDMA_CM_ADDRINFO_QUERY: CM is in the process of IB service
    resolution;
  - RDMA_CM_ADDRINFO_RESOLVED: CM has finished the resolve process.

With these new states, beside existing state transfer processes, 2 new
processes are supported:
 1. The default address is used:
    RDMA_CM_ADDR_BOUND ->
      RDMA_CM_ADDRINFO_QUERY ->
        RDMA_CM_ADDRINFO_RESOLVED ->
          RDMA_CM_ROUTE_QUERY

 2. To use a different address:
    RDMA_CM_ADDR_BOUND ->
      RDMA_CM_ADDRINFO_QUERY->
        RDMA_CM_ADDRINFO_RESOLVED ->
          RDMA_CM_ADDR_QUERY ->
            RDMA_CM_ADDR_RESOLVED ->
              RDMA_CM_ROUTE_QUERY

In the 2nd case, resolve_addrinfo returns multiple records, a user
could call rdma_resolve_addr() with the one that is not the first.

Signed-off-by: Or Har-Toov <ohartoov@nvidia.com>
Signed-off-by: Mark Zhang <markzhang@nvidia.com>
Reviewed-by: Vlad Dumitrescu <vdumitrescu@nvidia.com>
Link: https://patch.msgid.link/b6e82ad75522a13b5efe4ff86da0e465aab04cc2.1751279794.git.leonro@nvidia.com
Signed-off-by: Leon Romanovsky <leon@kernel.org>