[PATCH] uml: add modversions support

Actually, the real support was added by some earlier patches.  Now we simply
re-enable the config.  option.  I've actually tested it and it works well.

Signed-off-by: Paolo 'Blaisorblade' Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>