Merge branch 'introduce-unified-and-structured-phy'

Oleksij Rempel says:

====================
Introduce unified and structured PHY

This patch set introduces a unified and well-structured interface for
reporting PHY statistics. Instead of relying on arbitrary strings in PHY
drivers, this interface provides a consistent and structured way to
expose PHY statistics to userspace via ethtool.

The initial groundwork for this effort was laid by Jakub Kicinski, who
contributed patches to plumb PHY statistics to drivers and added support
for structured statistics in ethtool. Building on Jakub's work, I tested
the implementation with several PHYs, addressed a few issues, and added
support for statistics in two specific PHY drivers.

Most of changes are tracked in separate patches.
changes v6:
- drop ethtool_stat_add patch
changes v5:
- rebase against latest net-next
====================

Link: https://patch.msgid.link/20250110060517.711683-1-o.rempel@pengutronix.de
Signed-off-by: Paolo Abeni <pabeni@redhat.com>