Merge branch 'nfp-devlink-port-implementation'

Jakub Kicinski says:

====================
nfp: devlink port implementation

This series adds basic devlink support.  The operations we can perform
are port show and port split/unsplit.

v2:
Register devlink first, and then register all the ports.  Port {,un}split
searches the port list, which is protected by a mutex.  If port split
is requested before ports are registered we will simply not find the port
and return -EINVAL.
====================

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