usb: fix building musb drivers

Commit 3dacdf11 "usb: factor out state_string() on otg drivers"
broke building musb drivers since there is already another
otg_state_string() function in musb drivers, but with different
prototype. Fix musb drivers to use common otg_state_string(), too.

Also provide a nop for otg_state_string() if CONFIG_USB_OTG_UTILS
is not defined.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/musb/davinci.c b/drivers/usb/musb/davinci.c
index e6de097..3661b81 100644
--- a/drivers/usb/musb/davinci.c
+++ b/drivers/usb/musb/davinci.c
@@ -220,7 +220,8 @@
 	* status change events (from the transceiver) otherwise.
 	 */
 	devctl = musb_readb(mregs, MUSB_DEVCTL);
-	DBG(7, "poll devctl %02x (%s)\n", devctl, otg_state_string(musb));
+	DBG(7, "poll devctl %02x (%s)\n", devctl,
+		otg_state_string(musb->xceiv->state));
 
 	spin_lock_irqsave(&musb->lock, flags);
 	switch (musb->xceiv->state) {
@@ -356,7 +357,7 @@
 		davinci_musb_source_power(musb, drvvbus, 0);
 		DBG(2, "VBUS %s (%s)%s, devctl %02x\n",
 				drvvbus ? "on" : "off",
-				otg_state_string(musb),
+				otg_state_string(musb->xceiv->state),
 				err ? " ERROR" : "",
 				devctl);
 		retval = IRQ_HANDLED;