usb: dwc3: DWC_usb31 controller check

Add a convenience function to check if the controller is DWC_usb31.
Signed-off-by: John Youn <johnyoun@synopsys.com>
Signed-off-by: Felipe Balbi <balbi@kernel.org>

drivers/usb/dwc3/core.h

@@ -1024,6 +1024,12 @@ struct dwc3_gadget_ep_cmd_params {
 void dwc3_set_mode(struct dwc3 *dwc, u32 mode);
 int dwc3_gadget_resize_tx_fifos(struct dwc3 *dwc);
 
+/* check whether we are on the DWC_usb31 core */
+static inline bool dwc3_is_usb31(struct dwc3 *dwc)
+{
+	return !!(dwc->revision & DWC3_REVISION_IS_DWC31);
+}
+
 #if IS_ENABLED(CONFIG_USB_DWC3_HOST) || IS_ENABLED(CONFIG_USB_DWC3_DUAL_ROLE)
 int dwc3_host_init(struct dwc3 *dwc);
 void dwc3_host_exit(struct dwc3 *dwc);