net/smc: add SMC-Rv2 connection establishment

net/smc: add SMC-Rv2 connection establishment

BugLink: https://bugs.launchpad.net/bugs/1929035
Send a CLC proposal message, and the remote side process this type of
message and determine the target GID. Check for a valid route to this
GID, and complete the connection establishment.

Signed-off-by: Karsten Graul <kgraul@linux.ibm.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit e5c4744cfb598f98672f8d21d59ef2c1fa9c9b5f)
Signed-off-by: Frank Heimes <frank.heimes@canonical.com>
Acked-by: Tim Gardner <tim.gardner@canonical.com>