Merge branch 'mlxsw-Adapt-driver-to-upcoming-firmware-versions'

Ido Schimmel says:

====================
mlxsw: Adapt driver to upcoming firmware versions

The first two patches make sure that reserved fields are set to zero, as
required by the device's programmer's reference manual (PRM).

Last two patches prevent the driver from performing an invalid operation
that is going to be denied by upcoming firmware versions.
====================

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