extcon: arizona: Correct typo to disable regulation for button detection

We can use the bypass mode on the MICVDD reg for button detection, as
the comment in the code states, however the code was mistakenly
disabling bypass. This patch corrects this and allows bypass mode during
button detection.

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