rdma: Autoload netlink client modules

If a message comes in and we do not have the client in the table, then
try to load the module supplying that client using MODULE_ALIAS to find
it.

This duplicates the scheme seen in other netlink muxes (eg nfnetlink).

Signed-off-by: Jason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Doug Ledford <dledford@redhat.com>
diff --git a/drivers/infiniband/core/cma.c b/drivers/infiniband/core/cma.c
index d8edd8b..b76de2e 100644
--- a/drivers/infiniband/core/cma.c
+++ b/drivers/infiniband/core/cma.c
@@ -4537,5 +4537,7 @@ static void __exit cma_cleanup(void)
 	destroy_workqueue(cma_wq);
 }
 
+MODULE_ALIAS_RDMA_NETLINK(RDMA_NL_RDMA_CM, 1);
+
 module_init(cma_init);
 module_exit(cma_cleanup);