musb_hdrc: Stop VBUS draw on usb_gadget_unregister_driver

If musb_gadget_vbus_draw() also toggles a clock like tusb does,
USB clock will stay on after rmmoding a gadget driver. This
can block omap idle states.

Also handle disconnect as b_idle so that musb_gadget_vbus_draw()
gets called.
Signed-off-by: Tony Lindgren <tony@atomide.com>

drivers/usb/musb/musb_gadget.c

@@ -1842,6 +1842,9 @@ int usb_gadget_unregister_driver(struct usb_gadget_driver *driver)
 #endif
 
 	if (musb->gadget_driver == driver) {
+
+		(void) musb_gadget_vbus_draw(&musb->g, 0);
+
 		musb->xceiv.state = OTG_STATE_UNDEFINED;
 		stop_activity(musb, driver);
 

drivers/usb/musb/plat_uds.c

@@ -718,6 +718,7 @@ static irqreturn_t musb_stage2_irq(struct musb * musb, u8 bIntrUSB,
 #endif	/* OTG */
 #ifdef CONFIG_USB_GADGET_MUSB_HDRC
 		case OTG_STATE_B_PERIPHERAL:
+		case OTG_STATE_B_IDLE:
 			musb_g_disconnect(musb);
 			break;
 #endif	/* GADGET */