of: unittest: Convert to i2c's .probe_new()

In struct i2c_driver, field new_probe replaces the soon to be deprecated
field probe.  Update unittest for this change. The probe function
doesn't make use of the i2c_device_id * parameter so it can be trivially
converted.

Signed-off-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Reviewed-by: Frank Rowand <frowand.list@gmail.com>
Link: https://lore.kernel.org/r/20221118224540.619276-510-uwe@kleine-koenig.org


[robh: Add Frank's commit msg addition]
Signed-off-by: Rob Herring <robh@kernel.org>