staging: iio: sca3000 move to new event code scheme and add combined orientations

The combined orientations allow handling of typical motion and free fall
detectors to be handled as threshold events just applied to a number of
axes via boolean operations.  So freefall is when x, y and z magnitudes
are all below a threshold for a particular period.  Motion detectors
are typically whether x or y or z are above a particular value.

Signed-off-by: Jonathan Cameron <jic23@cam.ac.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>