Merge branch 's390-qeth-next'

Julian Wiedmann says:

====================
s390/qeth: updates 2020-09-10

subject to positive review by the bridge maintainers on patch 5,
please apply the following patch series to netdev's net-next tree.

Alexandra adds BR_LEARNING_SYNC support to qeth. In addition to the
main qeth changes (controlling the feature, and raising switchdev
events), this also needs
- Patch 1 and 2 for some s390/cio infrastructure improvements
  (acked by Heiko to go in via net-next), and
- Patch 5 to introduce a new switchdev_notifier_type, so that a driver
  can clear all previously learned entries from the bridge FDB in case
  things go out-of-sync later on.
====================

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