Merge branch 's390-next'

Julian Wiedmann says:

====================
s390/qeth: updates 2019-03-28

please apply the following patchset to net-next. This reworks the control
IO code in qeth so that we no longer need to poll for cmd completion,
and refactors the IDX setup code to also use this improved IO path.
====================

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