mfd: Switch two more drivers back to use struct i2c_driver::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>
Link: https://lore.kernel.org/r/20230626091941.557733-1-u.kleine-koenig@pengutronix.de


Signed-off-by: Lee Jones <lee@kernel.org>