Add controls to allow custom shaping of the ultrasonic response. This
custom shaping can be turned on/off at runtime, although, it should be
noted that settings will not affect a currently open audio stream,
they will be applied when the next audio stream is started.
Signed-off-by: NCharles Keepax <ckeepax@opensource.wolfsonmicro.com>
Signed-off-by: NMark Brown <broonie@linaro.org>