usb: gadget: add Faraday FOTG210 USB gadget support

The Faraday FOTG210 is an OTG chip which could operate
as either an EHCI Host or a USB Device at a time.

Signed-off-by: Kuo-Jung Su <dantesu@faraday-tech.com>
CC: Marek Vasut <marex@denx.de>
diff --git a/drivers/usb/gadget/gadget_chips.h b/drivers/usb/gadget/gadget_chips.h
index e570142..f038747 100644
--- a/drivers/usb/gadget/gadget_chips.h
+++ b/drivers/usb/gadget/gadget_chips.h
@@ -150,6 +150,12 @@
 #define gadget_is_mv(g)        0
 #endif
 
+#ifdef CONFIG_USB_GADGET_FOTG210
+#define gadget_is_fotg210(g)        (!strcmp("fotg210_udc", (g)->name))
+#else
+#define gadget_is_fotg210(g)        0
+#endif
+
 /*
  * CONFIG_USB_GADGET_SX2
  * CONFIG_USB_GADGET_AU1X00
@@ -215,5 +221,7 @@
 		return 0x20;
 	else if (gadget_is_mv(gadget))
 		return 0x21;
+	else if (gadget_is_fotg210(gadget))
+		return 0x22;
 	return -ENOENT;
 }