IPMI: fix SI address space settings

Fix a rather obvious error that Patrick found in the setup routines.  Need to
set the proper address space in the ACPI case.

Signed-off-by: Corey Minyard <minyard@acm.org>
Cc: Patrick Schoeller <Patrick.Schoeller@hp.com>
Cc: <stable@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>