can: kvaser_pciefd: Add support for ethtool set_phys_id()

Add support for ethtool set_phys_id(), to physically locate devices by
flashing a LED on the device.

Reviewed-by: Axel Forsman <axfo@kvaser.com>
Reviewed-by: Vincent Mailhol <mailhol.vincent@wanadoo.fr>
Signed-off-by: Jimmy Assarsson <extja@kvaser.com>
Link: https://patch.msgid.link/20250725123230.8-3-extja@kvaser.com


Signed-off-by: Marc Kleine-Budde <mkl@pengutronix.de>