usb: chipidea: add role init and destroy APIs

- The role's init will be called at probe procedure.
- The role's destroy will be called at fail patch
at probe and driver's removal.
- The role's start/stop will be called when specific
role has started.

Tested-by: Marek Vasut <marex@denx.de>
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/drivers/usb/chipidea/udc.h b/drivers/usb/chipidea/udc.h
index 455ac21..e66df00 100644
--- a/drivers/usb/chipidea/udc.h
+++ b/drivers/usb/chipidea/udc.h
@@ -84,6 +84,7 @@
 #ifdef CONFIG_USB_CHIPIDEA_UDC
 
 int ci_hdrc_gadget_init(struct ci_hdrc *ci);
+void ci_hdrc_gadget_destroy(struct ci_hdrc *ci);
 
 #else
 
@@ -92,6 +93,11 @@
 	return -ENXIO;
 }
 
+static inline void ci_hdrc_gadget_destroy(struct ci_hdrc *ci)
+{
+
+}
+
 #endif
 
 #endif /* __DRIVERS_USB_CHIPIDEA_UDC_H */