iio: accel: adxl372: introduce chip_info structure

iio: accel: adxl372: introduce chip_info structure

Introduce a chip_info structure to parameterize device-specific
properties such as ODR/bandwidth frequency tables, activity/inactivity
timer scale factors, and the maximum ODR value. This refactors the
driver to use chip_info lookups instead of hardcoded values, preparing
the driver to support multiple device variants.

The sampling_frequency and filter_low_pass_3db_frequency available
attributes are switched from custom sysfs callbacks to read_avail()
based handling via info_mask_shared_by_type_available. This enforces
consistent formatting through the IIO framework and makes the values
accessible to in-kernel consumers.

The SPI/I2C probe functions are updated to pass a chip_info pointer
instead of a device name string.

No functional change intended.

Signed-off-by: Antoniu Miclaus <antoniu.miclaus@analog.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>