USB: musb: fix Blackfin ulpi stubs

The new ulpi code defines fallback stubs for the Blackfin arch, but does
so incorrectly leading to a build failure:
drivers/usb/musb/musb_core.c:227: error: 'musb_ulpi_read' undeclared here (not in a function)
drivers/usb/musb/musb_core.c:228: error: 'musb_ulpi_write' undeclared here (not in a function)

Tweak the fallback stubs so that they do work as intended.
Signed-off-by: NMike Frysinger <vapier@gentoo.org>
Signed-off-by: NAjay Kumar Gupta <ajay.gupta@ti.com>
Acked-by: NFelipe Balbi <felipe.balbi@nokia.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@suse.de>

drivers/usb/musb/musb_core.c

@@ -219,8 +219,8 @@ static int musb_ulpi_write(struct otg_transceiver *otg,
 	return 0;
 }
 #else
-#define musb_ulpi_read(a, b)		NULL
-#define musb_ulpi_write(a, b, c)	NULL
+#define musb_ulpi_read		NULL
+#define musb_ulpi_write		NULL
 #endif
 
 static struct otg_io_access_ops musb_ulpi_access = {