Adds support to retrieve the enclosure and bay identifiers.  This patch
is from Eric with minor modifications from me, rewritten from a buggy
patch of mine, based on the earlier CSMI implementation from Eric..
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJames Bottomley <James.Bottomley@SteelEye.com>