staging:iio:events - new 64 bit code structure and push out drivers.

This costs us nothing in event storage (as we are carrying a 64 bit
timestamp in the structure) and gives us lots more room to play with.

Also allows for more channels which some parts need.

V2: Cleanup some loose ends (such as the switch with only one option now).

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