MAINTAINERS: Add ethtool pse-pd to PSE NETWORK DRIVER

Add net/ethtool/pse-pd.c to PSE NETWORK DRIVER to receive emails concerning
modifications to the ethtool part.

Reviewed-by: Oleksij Rempel <o.rempel@pengutronix.de>
Signed-off-by: Kory Maincent <kory.maincent@bootlin.com>
Reviewed-by: Simon Horman <horms@kernel.org>
Link: https://patch.msgid.link/20240909114336.362174-1-kory.maincent@bootlin.com


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