Workaround for SW192221 - simics multicast
Workaround for SW192221 - simics multicast

Working around a simics limitation with multicast scoms by
ignoring xscom errors that happen on multicast ops to group 7.
The workaround will be removed with RTC:67295.

Change-Id: Ide8191bec31284b09554e526349b0db7b92929f2
RTC: 67285
Reviewed-on: http://gfw160.austin.ibm.com:8080/gerrit/3694
Reviewed-by: Daniel M. Crowell <912029ca9254ac7b5854e56910561d682e1fa2d0@us.ibm.com>
Reviewed-by: Andrew J. Geissler <c46de238cd554860f0bd4010b1729f1323facd9c@us.ibm.com>
Tested-by: Jenkins Server
Reviewed-by: Dean Sanner <3b8f978f111a0718dcf88848e092ac780da17ab3@us.ibm.com>

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