Replace a netdev_info(), emitting an informational message about the
BTR value to be send to the controller, with a debug message by means
of netdev_dbg().

Link: https://lore.kernel.org/all/20230509-superglue-hazy-38108aa66bfa-mkl@pengutronix.de/Suggested-by: Marc Kleine-Budde <mkl@pengutronix.de>
Suggested-by: Vincent MAILHOL <mailhol.vincent@wanadoo.fr>
Signed-off-by: Frank Jungclaus <frank.jungclaus@esd.eu>
Link: https://lore.kernel.org/r/20230519195600.420644-7-frank.jungclaus@esd.euSigned-off-by: Marc Kleine-Budde <mkl@pengutronix.de>