Change duplicate usb_cpu_init_fail to usb_board_init_fail

Thanks to Liew Tsi Chung <Tsi-chung.Liew@freescale.com> for pointing
this out.

Signed-off-by: Markus Klotzbuecher <mk@denx.de>
diff --git a/drivers/usb_ohci.h b/drivers/usb_ohci.h
index 95fbc44..d2b03c0 100644
--- a/drivers/usb_ohci.h
+++ b/drivers/usb_ohci.h
@@ -10,7 +10,7 @@
 /* functions for doing board or CPU specific setup/cleanup */
 extern int usb_board_init(void);
 extern int usb_board_stop(void);
-extern int usb_cpu_init_fail(void);
+extern int usb_board_init_fail(void);
 
 extern int usb_cpu_init(void);
 extern int usb_cpu_stop(void);