Merge branch 'net-dsa-vsc73xx-convert-to-phylink-and-do-some-cleanup'

Pawel Dembicki says:

====================
net: dsa: vsc73xx: convert to PHYLINK and do some cleanup

This patch series is a result of splitting a larger patch series [0],
where some parts needed to be refactored.

The first patch switches from a poll loop to read_poll_timeout.

The second patch is a simple conversion to phylink because adjust_link
won't work anymore.

The third patch is preparation for future use. Using the
"phy_interface_mode_is_rgmii" macro allows for the proper recognition
of all RGMII modes.

Patches 4-5 involve some cleanup: The fourth patch introduces
a definition with the maximum number of ports to avoid using
magic numbers. The next one fills in documentation.

[0] https://patchwork.kernel.org/project/netdevbpf/list/?series=841034&state=%2A&archive=both
====================

Link: https://lore.kernel.org/r/20240417205048.3542839-1-paweldembicki@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>