extcon: max8997: Set default UART/USB path on probe

This patch set default H/W line path according to platfomr data.
The MAX8997 MUIC device can possibly set UART/USB or UART_AUX
/USB_AUX to internal H/W line path of MUIC device. Namely, only
one H/W line is used for two operation.

For example,
if H/W line path of MAX8997 device set UART/USB, micro usb cable
is connected to AP(Application Processor) and if H/W line path
set UART_AUX/USB_AUX, micro usb cable is connected to CP(Coprocessor).

Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Myungjoo Ham <myungjoo.ham@samsung.com>