extcon: arizona: Declare 3-pole jack if we detect open circuit on mic

Detecting an open-circuit on the microphone pin, usually means the
headset has a microphone but the cable is faulty. Currently the code
will simply stop detecting and declare nothing in this situation. It is
better to declare this as headphones such that the user can still use
their headset as plain headphones even if the microphone is faulty.

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