usb: musb: omap2430: fix build failure

Fix build failure introduced by commit
7acc6197 (usb: musb: Idle path retention
and offmode support for OMAP3) when building without gadget
support.

  CC      drivers/usb/musb/omap2430.o
drivers/usb/musb/omap2430.c: In function ‘musb_otg_notifications’:
drivers/usb/musb/omap2430.c:262: error: ‘struct musb’ has no member named ‘gadget_driver’
Signed-off-by: Johan Hovold <jhovold@gmail.com>
Cc: Felipe Balbi <balbi@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/usb/musb/omap2430.c

@@ -259,9 +259,10 @@ static int musb_otg_notifications(struct notifier_block *nb,
 	case USB_EVENT_VBUS:
 		DBG(4, "VBUS Connect\n");
 
+#ifdef CONFIG_USB_GADGET_MUSB_HDRC
 		if (musb->gadget_driver)
 			pm_runtime_get_sync(musb->controller);
-
+#endif
 		otg_init(musb->xceiv);
 		break;