extcon: arizona: Add device binding to enable ADC mode micdet

Add a simple boolean binding to turn on and off the use of ADC
microphone detection mode to determine 3/4 pole jack.

Signed-off-by: Charles Keepax <ckeepax@opensource.wolfsonmicro.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>