Fix bad address discovered in VPO multichip config
Fix bad address discovered in VPO multichip config

Details abound in CQ HW226693.  Basically the code was accessing
the wrong register address because of some bad byte/word math.
The hardware flagged an error on the outbound message as soon as
we attempted a write to 1830D1.

Change-Id: Ie36cb44349d1e896a5a7e3962150dbdf265cfadf
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/2291
Tested-by: Jenkins Server
Reviewed-by: A. Patrick Williams III <c87e37b1a4035affd737b461af89fb722d635f4d@us.ibm.com>

open-power/hostboot,alvintpwang/hostboot,open-power/hostboot,Over-enthusiastic/hostboot,csmart/hostboot,csmart/hostboot,alvintpwang/hostboot,alvintpwang/hostboot,csmart/hostboot,alvintpwang/hostboot,open-power/hostboot,csmart/hostboot,open-power/hostboot,open-power/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot,Over-enthusiastic/hostboot,alvintpwang/hostboot,Over-enthusiastic/hostboot,csmart/hostboot