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.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/Kconfig

@@ -254,6 +254,11 @@ config ARCH_SUPPORTS_OPTIMIZED_INLINING
 config ARCH_SUPPORTS_DEBUG_PAGEALLOC
 	def_bool y
 
+config KASAN_SHADOW_OFFSET
+	hex
+	depends on KASAN
+	default 0xdffffc0000000000
+
 config HAVE_INTEL_TXT
 	def_bool y
 	depends on INTEL_IOMMU && ACPI

lib/Kconfig.kasan

@@ -18,10 +18,6 @@ config KASAN
 	  For better error detection enable CONFIG_STACKTRACE,
 	  and add slub_debug=U to boot cmdline.
 
-config KASAN_SHADOW_OFFSET
-	hex
-	default 0xdffffc0000000000 if X86_64
-
 choice
 	prompt "Instrumentation type"
 	depends on KASAN