aio: add calls for changing bit value of the read

Signed-off-by: Thomas Ingleby <thomas.c.ingleby@intel.com>
doc: add ADC information for each platform

Signed-off-by: Thomas Ingleby <thomas.c.ingleby@intel.com>
aio: change return from uint16 to unsigned int

Signed-off-by: Thomas Ingleby <thomas.c.ingleby@intel.com>