iio: Add driver for Nicera D3-323-AA PIR sensor

Nicera D3-323-AA is a PIR sensor for human detection. It has support for
raw data measurements and detection notification. The communication
protocol is custom made and therefore needs to be GPIO bit banged.

The device has two main settings that can be configured: a threshold
value for detection and a band-pass filter. The configurable parameters
for the band-pass filter are the high-pass and low-pass cutoff
frequencies and its peak gain. Map these settings to the corresponding
parameters in the `iio` framework.

Raw data measurements can be obtained from the device. However, since we
rely on bit banging, it will be rather cumbersome with buffer support.
The main reason being that the data protocol has strict timing
requirements (it's serial like UART), and it's mainly used during
debugging since in real-world applications only the event notification
is of importance. Therefore, only add support for events (for now).

Signed-off-by: Waqar Hameed <waqar.hameed@axis.com>
Link: https://patch.msgid.link/29f84da1431f4a3f17fdeef27297a4ab14455404.1751636734.git.waqar.hameed@axis.com


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