usb: otg: prefix otg_state_string with usb_

all other functions under drivers/usb/ start
with usb_, let's do the same thing.

This patch is in preparation for moving otg_state_string
to usb-common.c and deleting otg.c completely.

Signed-off-by: Felipe Balbi <balbi@ti.com>
diff --git a/drivers/usb/musb/musb_dsps.c b/drivers/usb/musb/musb_dsps.c
index 4b49874..1ea553d 100644
--- a/drivers/usb/musb/musb_dsps.c
+++ b/drivers/usb/musb/musb_dsps.c
@@ -225,7 +225,7 @@
 	 */
 	devctl = dsps_readb(mregs, MUSB_DEVCTL);
 	dev_dbg(musb->controller, "Poll devctl %02x (%s)\n", devctl,
-				otg_state_string(musb->xceiv->state));
+				usb_otg_state_string(musb->xceiv->state));
 
 	spin_lock_irqsave(&musb->lock, flags);
 	switch (musb->xceiv->state) {
@@ -274,7 +274,7 @@
 	if (musb->is_active || (musb->a_wait_bcon == 0 &&
 				musb->xceiv->state == OTG_STATE_A_WAIT_BCON)) {
 		dev_dbg(musb->controller, "%s active, deleting timer\n",
-				otg_state_string(musb->xceiv->state));
+				usb_otg_state_string(musb->xceiv->state));
 		del_timer(&glue->timer[pdev->id]);
 		glue->last_timer[pdev->id] = jiffies;
 		return;
@@ -289,7 +289,7 @@
 	glue->last_timer[pdev->id] = timeout;
 
 	dev_dbg(musb->controller, "%s inactive, starting idle timer for %u ms\n",
-		otg_state_string(musb->xceiv->state),
+		usb_otg_state_string(musb->xceiv->state),
 			jiffies_to_msecs(timeout - jiffies));
 	mod_timer(&glue->timer[pdev->id], timeout);
 }
@@ -378,7 +378,7 @@
 		/* NOTE: this must complete power-on within 100 ms. */
 		dev_dbg(musb->controller, "VBUS %s (%s)%s, devctl %02x\n",
 				drvvbus ? "on" : "off",
-				otg_state_string(musb->xceiv->state),
+				usb_otg_state_string(musb->xceiv->state),
 				err ? " ERROR" : "",
 				devctl);
 		ret = IRQ_HANDLED;