RDMA CM: Add reason code for IB_CM_REJ_CONSUMER_DEFINED

RDMA CM: Add reason code for IB_CM_REJ_CONSUMER_DEFINED

RDS: Support rolling downgrade from version 4.1 to 3.1

Orabug: 17484682

Signed-off-by: Giri Adari <giri.adari@oracle.com>
Signed-off-by: Richard Frank <richard.frank@oracle.com>
Signed-off-by: Chien-Hua Yen <chien.yen@oracle.com>
(cherry picked from commit 7b66ddd7f6a5b023191d74949fab41af245775a3)
Signed-off-by: Jerry Snitselaar <jerry.snitselaar@oracle.com>
Conflicts:
	net/rds/rds.h
(cherry picked from commit 0373566ba0d74f655ae83e09748f7cc8d553f351)