The original check was apparently to work around some old BIOS bugs and we
just assume x86-64 machines don't have this class of problems.

Originally found by <YhLu@tyan.com>
Signed-off-by: Andi Kleen <ak@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>