Merge branch 'mlxsw-RJ45'

Ido Schimmel says:

====================
mlxsw: Add RJ45 ports support

We are in the process of qualifying a new system that has RJ45 ports as
opposed to the transceiver modules (e.g., SFP, QSFP) present on all
existing systems.

This patchset adds support for these ports in mlxsw by adding a couple of
missing BaseT link modes and rejecting ethtool operations that are
specific to transceiver modules.

Patchset overview:

Patches #1-#3 are cleanups and preparations.

Patch #4 adds support for two new link modes.

Patches #5-#6 query and cache the port module's type (e.g., QSFP, RJ45)
during initialization.

Patches #7-#9 forbid ethtool operations that are invalid on RJ45 ports.
====================

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