extcon: arizona: Remove unnecessary sets of ACCDET_MODE

arizona_start_mic sets ACCDET_MODE as required for the microphone
detection as such it is redundant to set this outside of this function.

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