powerpc: Fix wrong defintion in boot/io.h

Fix wrong __IO_H definition in boot/io.h

Reported-by: Fernando Silveira <[email protected]>
Signed-off-by: Lucas Tanure <[email protected]>
Signed-off-by: Benjamin Herrenschmidt <[email protected]>

Author: lucastanure

arch/powerpc/boot/io.h

@@ -1,5 +1,5 @@
 #ifndef _IO_H
-#define __IO_H
+#define _IO_H
 
 #include "types.h"