usb: musb: Blackfin provides read/write I/O accessor in header files

Don't redefine the functions in musb driver
Signed-off-by: Bryan Wu <cooloney@kernel.org>
Signed-off-by: Felipe Balbi <felipe.balbi@nokia.com>

drivers/usb/musb/musb_io.h

@@ -39,7 +39,7 @@
 
 #if !defined(CONFIG_ARM) && !defined(CONFIG_SUPERH) \
 	&& !defined(CONFIG_AVR32) && !defined(CONFIG_PPC32) \
-	&& !defined(CONFIG_PPC64)
+	&& !defined(CONFIG_PPC64) && !defined(CONFIG_BLACKFIN)
 static inline void readsl(const void __iomem *addr, void *buf, int len)
 	{ insl((unsigned long)addr, buf, len); }
 static inline void readsw(const void __iomem *addr, void *buf, int len)