Allow the application to choose if the ADC data presented on the left
and right channels is sourced from the internal left or right channel.
This allows a mono recording to be presented as stereo on the external
bus.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Liam Girdwood <lrg@slimlogic.co.uk>