dt-bindings: usb: richtek,rt1711h: Add missing vbus power supply

The RichTek RT1711H and RT1719 chips do have a vbus pin that is
used for attach/detach detection (respectively, pin A1 and 11):
allow a vbus-supply phandle for that.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Link: https://lore.kernel.org/r/20250219140143.104037-1-angelogioacchino.delregno@collabora.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>