fsi: i2cr: Switch to use struct i2c_driver's .probe()

struct i2c_driver::probe_new is about to go away. Switch the driver to
use the probe callback with the same prototype.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Eddie James <eajames@linux.ibm.com>
Reviewed-by: Joel Stanley <joel@jms.id.au>
Link: https://lore.kernel.org/r/20230816171944.123705-1-u.kleine-koenig@pengutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>