usb: dwc2: don't use ID/Vbus detection if usb-role-switch on STM32MP15 SoCs
If usb-role-switch is present in the device tree, it means that ID and Vbus
signals are not connected to the OTG controller but to an external
component (GPIOs, Type-C controller). In this configuration, usb role
switch is used to force valid sessions on STM32MP15 SoCs.