extcon: max8997: Fix lack of path setting in USB device mode

MAX8997 driver disables automatic path selection from MicroUSB connector
and manually sets path to either UART or USB lines. However the code for
setting USB path worked only for USB host mode (when ID pin is set
to ground). When standard USB cable (USB device mode) is connected, path
registers are not touched. This means that once the non-USB accessory is
connected to MAX8997-operated micro USB port, the path is no longer set
to USB and USB device mode doesn't work. This patch fixes it by setting
USB path both for USB and USB host modes.

Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>