EDAC/igen6: fix core dependency AGAIN

My previous patch had a typo/thinko which prevents this driver
from being enabled: change X64_64 to X86_64.

Fixes: 0a9ece9b

 ("EDAC/igen6: fix core dependency")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Qiuxu Zhuo <qiuxu.zhuo@intel.com>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Mauro Carvalho Chehab <mchehab@kernel.org>
Cc: linux-edac@vger.kernel.org
Cc: bowsingbetee <bowsingbetee@protonmail.com>
Cc: stable@vger.kernel.org
Signed-off-by: Tony Luck <tony.luck@intel.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>