mca: add integrated device bus matching

The MCA bus has a few "integrated" functions, which are effectively virtual
slots on the bus.  The problem is that these special functions don't have
dedicated pos IDs, so we have to manufacture ids for them outside the pos
space ...  and these ids can't be matched by the standard matching function,
so add a special registration that requests a list of pos ids or a particular
integrated function.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>