x86: fix header export, asm-x86/processor-flags.h, CONFIG_* leaks

Apparently,

commit 6330a30a
Author: Vegard Nossum <vegard.nossum@gmail.com>
Date:   Wed May 28 09:46:19 2008 +0200

    x86: break mutual header inclusion

introduced some CONFIG names to processor-flags.h, which was exported in

commit 6093015d


Author: Ingo Molnar <mingo@elte.hu>
Date:   Sun Mar 30 11:45:23 2008 +0200

    x86: cleanup replace most vm86 flags with flags from processor-flags.h, fix

Fix it by wrapping the CONFIG parts in __KERNEL__.

Reported-by: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Vegard Nossum <vegard.nossum@gmail.com>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Olaf Hering <olaf@aepfle.de>
Signed-off-by: Ingo Molnar <mingo@elte.hu>