RDMA/ucma: Deliver ECE parameters through UCMA events

Passive side of CMID connection receives ECE request through REQ message
and needs to respond with relevant REP message which will be forwarded to
active side.

The UCMA events interface is responsible for such communication with the
user space (librdmacm). Extend it to provide ECE wire data.

Link: https://lore.kernel.org/r/20200526103304.196371-4-leon@kernel.org
Signed-off-by: Leon Romanovsky <leonro@mellanox.com>
Signed-off-by: Jason Gunthorpe <jgg@mellanox.com>

include/uapi/rdma/rdma_user_cm.h

@@ -297,6 +297,7 @@ struct rdma_ucm_event_resp {
 		struct rdma_ucm_ud_param   ud;
 	} param;
 	__u32 reserved;
+	struct rdma_ucm_ece ece;
 };
 
 /* Option levels */