Merge branch 'devlink-expose-instance-locking-and-simplify-port-splitting'

Jakub Kicinski says:

====================
devlink: expose instance locking and simplify port splitting

This series puts the devlink ports fully under the devlink instance
lock's protection. As discussed in the past it implements my preferred
solution of exposing the instance lock to the drivers. This way drivers
which want to support port splitting can lock the devlink instance
themselves on the probe path, and we can take that lock in the core
on the split/unsplit paths.

nfp and mlxsw are converted, with slightly deeper changes done in
nfp since I'm more familiar with that driver.

Now that the devlink port is protected we can pass a pointer to
the drivers, instead of passing a port index and forcing the drivers
to do their own lookups. Both nfp and mlxsw can container_of() to
their own structures.
====================

Link: https://lore.kernel.org/r/20220315060009.1028519-1-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>