power: Update the multiple inclusion protection symbol on machdep.h

Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/include/asm-powerpc/machdep.h b/include/asm-powerpc/machdep.h
index b3a93b4..706508b 100644
--- a/include/asm-powerpc/machdep.h
+++ b/include/asm-powerpc/machdep.h
@@ -1,5 +1,5 @@
-#ifndef _PPC64_MACHDEP_H
-#define _PPC64_MACHDEP_H
+#ifndef _ASM_POWERPC_MACHDEP_H
+#define _ASM_POWERPC_MACHDEP_H
 #ifdef __KERNEL__
 
 /*
@@ -281,4 +281,4 @@
 }
 
 #endif /* __KERNEL__ */
-#endif /* _PPC64_MACHDEP_H */
+#endif /* _ASM_POWERPC_MACHDEP_H */