extcon: arizona: No need to switch back down HPDET ranges

No point in revisiting ranges the detection will be no more accurate
the second time simply report that the resistance is right on the
range boundry.

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