rdma: Allow demand loading of NETLINK_RDMA

Provide a module alias so that if userspace opens a netlink
socket for RDMA the kernel support is loaded automatically.
Signed-off-by: NJason Gunthorpe <jgunthorpe@obsidianresearch.com>
Reviewed-by: NLeon Romanovsky <leonro@mellanox.com>
Signed-off-by: NDoug Ledford <dledford@redhat.com>

drivers/infiniband/core/netlink.c

@@ -38,6 +38,7 @@
 #include <net/net_namespace.h>
 #include <net/sock.h>
 #include <rdma/rdma_netlink.h>
+#include <linux/module.h>
 #include "core_priv.h"
 
 #include "core_priv.h"
@@ -290,3 +291,5 @@ void rdma_nl_exit(void)
 
 	netlink_kernel_release(nls);
 }
+
+MODULE_ALIAS_NET_PF_PROTO(PF_NETLINK, NETLINK_RDMA);