iio: adc: nau7802: Convert driver to use ->probe_new()

Use the ->probe_new() callback.

The driver does not use const struct i2c_device_id * argument,
so convert it to utilise the simplified I²C driver registration.

Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/20220531213922.72992-1-andriy.shevchenko@linux.intel.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>