Merge branch 'rework-dsa-bridge-tx-forwarding-offload-api'

Vladimir Oltean says:

====================
Rework DSA bridge TX forwarding offload API

This change set is preparation work for DSA support of bridge FDB
isolation. It replaces struct net_device *dp->bridge_dev with a struct
dsa_bridge *dp->bridge that contains some extra information about that
bridge, like a unique number kept by DSA.

Up until now we computed that number only with the bridge TX forwarding
offload feature, but it will be needed for other features too, like for
isolation of FDB entries belonging to different bridges. Hardware
implementations vary, but one common pattern seems to be the presence of
a FID field which can be associated with that bridge number kept by DSA.
The idea was outlined here:
https://patchwork.kernel.org/project/netdevbpf/patch/20210818120150.892647-16-vladimir.oltean@nxp.com/
(the difference being that with this new proposal, drivers would not
need to call dsa_bridge_num_find, instead the bridge_num would be part
of the struct dsa_bridge :: num passed as argument).

No functional change is intended for drivers that don't already make use
of the bridge TX forwarding offload. I've tested the changes on the
felix, sja1105 and mv88e6xxx drivers, but nonetheless I'm copying all
DSA driver maintainers due to API changes that are taking place.

Compared to v1 and v2, the amount of patches is larger, but the contents
is mostly the same, just split up hopefully a bit better for review.
====================

Link: https://lore.kernel.org/r/20211206165758.1553882-1-vladimir.oltean@nxp.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>