extcon: arizona: Update DT binding documentation for jack detection

Add additional bindings for both inverting the polarity of the jack
detection pins and allowing the use of a second jack detection pin. Note
that the second jack detection pin is hard wired in the chip so can only
be enabled through the binding, rather than a pin being specified.

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