x86/kasan: Move KASAN_SHADOW_OFFSET to the arch Kconfig

KASAN_SHADOW_OFFSET is purely arch specific setting,
so it should be in arch's Kconfig file.

Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com>
Cc: Alexander Popov <alpopov@ptsecurity.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Andrey Konovalov <adech.fo@gmail.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Dmitry Vyukov <dvyukov@google.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Paul Bolle <pebolle@tiscali.nl>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1435828178-10975-7-git-send-email-a.ryabinin@samsung.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>
Git-Commit: d6f2d75a7ae06ffd793bb504c4f0d1665548cffc
Git repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Jeevan Shriram <jshriram@codeaurora.org>