usb: dwc2: allow peripheral mode for OTG configuration

Allow device mode in DWC2 driver when device tree select the dr_mode
"peripheral" or "otg".

The device mode is not allowed when dr_mode = "host" in device tree.

Signed-off-by: Patrick Delaunay <patrick.delaunay@st.com>
Reviewed-by: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/gadget/dwc2_udc_otg.c b/drivers/usb/gadget/dwc2_udc_otg.c
index 023439c..35f4147 100644
--- a/drivers/usb/gadget/dwc2_udc_otg.c
+++ b/drivers/usb/gadget/dwc2_udc_otg.c
@@ -1041,7 +1041,8 @@
 	void (*set_params)(struct dwc2_plat_otg_data *data);
 	int ret;
 
-	if (usb_get_dr_mode(node) != USB_DR_MODE_PERIPHERAL) {
+	if (usb_get_dr_mode(node) != USB_DR_MODE_PERIPHERAL &&
+	    usb_get_dr_mode(node) != USB_DR_MODE_OTG) {
 		dev_dbg(dev, "Invalid mode\n");
 		return -ENODEV;
 	}