iio: proximity: Add driver support for TYHX's HX9023S capacitive proximity sensor

A SAR sensor from NanjingTianyihexin Electronics Ltd.

The device has the following entry points:

Usual frequency:
- sampling_frequency

Instant reading of current values for different sensors:
- in_proximity0_raw
- in_proximity1_raw
- in_proximity2_raw
- in_proximity3_raw
- in_proximity4_raw
and associated events in events/

Signed-off-by: Yasin Lee <yasin.lee.x@gmail.com>
Link: https://patch.msgid.link/20240702-add-tyhx-hx9023s-sensor-driver-v9-3-c030f1801d9b@gmail.com


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