Merge branch 'mlxsw-Spectrum-2-PTP-preparations'

Ido Schimmel says:

====================
mlxsw: Spectrum-2 PTP preparations

This patchset includes various preparations required for Spectrum-2 PTP
support.

Most of the changes are non-functional (e.g., renaming, adding
registers). The only intentional user visible change is in patch #10
where the PHC time is initialized to zero in accordance with the
recommendation of the PTP maintainer.
====================

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