Add SLIT (inter node distance) information to sysfs.

[This is Jack's patch that he submitted on l-k. I'm submitting
it for him because I need it for my x86-64 followon SLIT patch.
Hope I don't stomp onto his toes with that one. If you already 
merged it please ignore]

From: Jack Steiner

Here is an update patch to externalize the SLIT information. I think I have
encorporated all the comments that were posted previously)

For example:

        # cd /sys/devices/system
        # find .
        ./node
        ./node/node5
        ./node/node5/distance
        ./node/node5/numastat
        ./node/node5/meminfo
        ./node/node5/cpumap

        # cat ./node/node0/distance
        10 20 64 42 42 22

        # cat node/*/distance
        10 20 64 42 42 22
        20 10 42 22 64 84
        64 42 10 20 22 42
        42 22 20 10 42 62
        42 64 22 42 10 20
        22 84 42 62 20 10
Signed-off-by: Jack Steiner <steiner@sgi.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>