usb: chipidea: add vbus interrupt handler

We add vbus interrupt handler at ci_otg_work, it uses OTGSC_BSV(at otgsc)
to know it is connect or disconnet event.
Meanwhile, we introduce two flags id_event and b_sess_valid_event to
indicate it is an id interrupt or a vbus interrupt.

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/otg.h b/drivers/usb/chipidea/otg.h
index 8acf3df..2d9f090 100644
--- a/drivers/usb/chipidea/otg.h
+++ b/drivers/usb/chipidea/otg.h
@@ -30,5 +30,6 @@
 int ci_hdrc_otg_init(struct ci_hdrc *ci);
 void ci_hdrc_otg_destroy(struct ci_hdrc *ci);
 enum ci_role ci_otg_role(struct ci_hdrc *ci);
+void ci_handle_vbus_change(struct ci_hdrc *ci);
 
 #endif /* __DRIVERS_USB_CHIPIDEA_OTG_H */