Use AccelScale, which supports per-axis accelerometer scaling everywhere
we would have had a single scale value.
This adds per-axis support from the ring-buffer for accelerometers
with triggers.
Properties with the IIO_SHARED_BY_ALL mask don't have the sensor type prefix
before the filename, causing some devices to not have a scale set from sysfs.
Fix this by searching through sysfs for both properties name: scale and
in_accel_scale.
Tested on: Cyan (Acer Chromebook R11, with 2 accelerometers)
Affects: All chromebooks with cros-ec sensors
https://github.com/torvalds/linux/tree/master/drivers/iio/common/cros_ec_sensors
