net: ethtool: Add PSE port priority support feature

This patch expands the status information provided by ethtool for PSE c33
with current port priority and max port priority. It also adds a call to
pse_ethtool_set_prio() to configure the PSE port priority.

Signed-off-by: Kory Maincent (Dent Project) <kory.maincent@bootlin.com>
Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Link: https://patch.msgid.link/20250617-feature_poe_port_prio-v14-8-78a1a645e2ee@bootlin.com


Signed-off-by: Jakub Kicinski <kuba@kernel.org>