usb: common: of_usb_get_dr_mode to usb_get_dr_mode

By using the unified device property interface, the function
can be made available for all platforms and not just the
ones using DT.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/dwc3/dwc3-st.c b/drivers/usb/dwc3/dwc3-st.c
index 02d47d5..5c0adb9 100644
--- a/drivers/usb/dwc3/dwc3-st.c
+++ b/drivers/usb/dwc3/dwc3-st.c
@@ -268,7 +268,7 @@
 		goto undo_softreset;
 	}
 
-	dwc3_data->dr_mode = of_usb_get_dr_mode(child_pdev->dev.of_node);
+	dwc3_data->dr_mode = usb_get_dr_mode(&child_pdev->dev);
 
 	/*
 	 * Configure the USB port as device or host according to the static