usb: dwc2: add support for external vbus supply

Some board do not use the dwc2 internal VBUS_DRV signal, but
use a gpio pin to enable the 5.0V VBUS power, add interface to
enable the power in dwc2 driver.

Signed-off-by: Kever Yang <kever.yang@rock-chips.com>
Signed-off-by: Simon Glass <sjg@chromium.org>
1 file changed