extcon: usb-gpio: Add pinctrl operation during system PM

At some systems, the pinctrl setting will be lost or needs to
set as "sleep" state to save power consumption. So, we need to
configure pinctrl as "sleep" state when system enters suspend,
and as "default" state after system resumes. In this way, the
pinctrl value can be recovered as "default" state after resuming.

Signed-off-by: Peter Chen <peter.chen@nxp.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>