usb: factor out state_string() on otg drivers

Provide common otg_state_string() and use
it in drivers.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
diff --git a/drivers/usb/otg/isp1301_omap.c b/drivers/usb/otg/isp1301_omap.c
index e25700f..8c28225 100644
--- a/drivers/usb/otg/isp1301_omap.c
+++ b/drivers/usb/otg/isp1301_omap.c
@@ -234,29 +234,9 @@
 
 /*-------------------------------------------------------------------------*/
 
-static const char *state_string(enum usb_otg_state state)
-{
-	switch (state) {
-	case OTG_STATE_A_IDLE:		return "a_idle";
-	case OTG_STATE_A_WAIT_VRISE:	return "a_wait_vrise";
-	case OTG_STATE_A_WAIT_BCON:	return "a_wait_bcon";
-	case OTG_STATE_A_HOST:		return "a_host";
-	case OTG_STATE_A_SUSPEND:	return "a_suspend";
-	case OTG_STATE_A_PERIPHERAL:	return "a_peripheral";
-	case OTG_STATE_A_WAIT_VFALL:	return "a_wait_vfall";
-	case OTG_STATE_A_VBUS_ERR:	return "a_vbus_err";
-	case OTG_STATE_B_IDLE:		return "b_idle";
-	case OTG_STATE_B_SRP_INIT:	return "b_srp_init";
-	case OTG_STATE_B_PERIPHERAL:	return "b_peripheral";
-	case OTG_STATE_B_WAIT_ACON:	return "b_wait_acon";
-	case OTG_STATE_B_HOST:		return "b_host";
-	default:			return "UNDEFINED";
-	}
-}
-
 static inline const char *state_name(struct isp1301 *isp)
 {
-	return state_string(isp->otg.state);
+	return otg_state_string(isp->otg.state);
 }
 
 /*-------------------------------------------------------------------------*/
@@ -501,7 +481,7 @@
 	if (isp->otg.state == state && !extra)
 		return;
 	pr_debug("otg: %s FSM %s/%02x, %s, %06x\n", tag,
-		state_string(state), fsm, state_name(isp),
+		otg_state_string(state), fsm, state_name(isp),
 		omap_readl(OTG_CTRL));
 }
 
@@ -1095,7 +1075,7 @@
 
 	if (state != isp->otg.state)
 		pr_debug("  isp, %s -> %s\n",
-				state_string(state), state_name(isp));
+				otg_state_string(state), state_name(isp));
 
 #ifdef	CONFIG_USB_OTG
 	/* update the OTG controller state to match the isp1301; may