Merge branch 'net-smc-introduce-SMC-Dv2-support'

Karsten Graul says:

====================
net/smc: introduce SMC-Dv2 support

SMC-Dv2 support (see https://www.ibm.com/support/pages/node/6326337)
provides multi-subnet support for SMC-D, eliminating the current
same-subnet restriction. The new version detects if any of the virtual
ISM devices are on the same system and can therefore be used for an
SMC-Dv2 connection. Furthermore, SMC-Dv2 eliminates the need for
PNET IDs on s390.
====================

Signed-off-by: David S. Miller <davem@davemloft.net>