powerpc: mman.h export fixups

Commit ef3d3246 ("powerpc/mm: Add Strong
Access Ordering support") in the powerpc/{next,master} tree caused the
following in a powerpc allmodconfig build:

usr/include/asm/mman.h requires linux/mm.h, which does not exist in exported headers

We should not use CONFIG_PPC64 in an unprotected (by __KERNEL__)
section of an exported include file and linux/mm.h is not exported.  So
protect the whole section that is CONFIG_PPC64 with __KERNEL__ and put
the two introduced includes in there as well.
Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Acked-by: Dave Kleikamp <shaggy@linux.vnet.ibm.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>

include/asm-powerpc/Kbuild

@@ -2,7 +2,6 @@ include include/asm-generic/Kbuild.asm
 
 header-y += auxvec.h
 header-y += ioctls.h
-header-y += mman.h
 header-y += sembuf.h
 header-y += siginfo.h
 header-y += stat.h

include/asm-powerpc/mman.h

 #ifndef _ASM_POWERPC_MMAN_H
 #define _ASM_POWERPC_MMAN_H
 
-#include <asm/cputable.h>
 #include <asm-generic/mman.h>
-#include <linux/mm.h>
 
 /*
  * This program is free software; you can redistribute it and/or
@@ -28,7 +26,12 @@
 #define MAP_POPULATE	0x8000		/* populate (prefault) pagetables */
 #define MAP_NONBLOCK	0x10000		/* do not block on IO */
 
+#ifdef __KERNEL__
 #ifdef CONFIG_PPC64
+
+#include <asm/cputable.h>
+#include <linux/mm.h>
+
 /*
  * This file is included by linux/mman.h, so we can't use cacl_vm_prot_bits()
  * here.  How important is the optimization?
@@ -56,4 +59,5 @@ static inline int arch_validate_prot(unsigned long prot)
 #define arch_validate_prot(prot) arch_validate_prot(prot)
 
 #endif /* CONFIG_PPC64 */
+#endif /* __KERNEL__ */
 #endif	/* _ASM_POWERPC_MMAN_H */