drivers: usb: usb_dc_it82xx2: correct the resumed/suspended mechanism

This change corrects the it82xx2 resumed/suspended mechanism and power
policy flow. The sof package is used to judge if the device can be set as
suspended state. If there is no sof package received(suspended), the chip
power policy is set as standby(deep doze) mode. Meanwhile, the USB D+
interrupt is enabled. The interrupt is triggered at resume signal(from J
to K state). Chip sets its power state as active(doze) mode and disable
the interrupt.

Signed-off-by: Ren Chen <Ren.Chen@ite.com.tw>