regulator: ad5398: Convert to i2c's .probe_new()

regulator: ad5398: Convert to i2c's .probe_new()

.probe_new() doesn't get the i2c_device_id * parameter, so determine
that explicitly in the probe function.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Acked-by: Michael Hennerich <michael.hennerich@analog.com>
Acked-for-MFD-by: Lee Jones <lee@kernel.org>
Acked-for-Backlight-by: Lee Jones <lee@kernel.org>
Link: https://lore.kernel.org/r/20221118224540.619276-540-uwe@kleine-koenig.org
Signed-off-by: Mark Brown <broonie@kernel.org>