iio: accel: Support Kionix/ROHM KX022A accelerometer

KX022A is a 3-axis accelerometer from ROHM/Kionix. The sensor features
include variable ODRs, I2C and SPI control, FIFO/LIFO with watermark IRQ,
tap/motion detection, wake-up & back-to-sleep events, four acceleration
ranges (2, 4, 8 and 16g), and probably some other cool features.

Add support for the basic accelerometer features such as getting the
acceleration data via IIO. (raw reads, triggered buffer [data-ready] or
using the WMI IRQ).

Important things to be added include the double-tap, motion
detection and wake-up as well as the runtime power management.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://lore.kernel.org/r/758b00d6aea0a6431a5a3a78d557d449c113b21e.1666614295.git.mazziesaccount@gmail.com


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