Fix up memory mirroring base address on non 0 nodes

  Math was incorrect -- NODAL offset is always group 0
  chip 0, no need to divide by 2

Change-Id: Ia34088121fdfa9d2a2fda6763c28cb5942ae1f3f
CQ:SW432908
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/60920
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Reviewed-by: Nicholas E. Bofferding <bofferdn@us.ibm.com>

src/usr/isteps/istep14/call_proc_exit_cache_contained.C

@@ -225,7 +225,7 @@ void* call_proc_exit_cache_contained (void *io_pArgs)
                 uint64_t this_node = PIR_t(task_getcpuid()).groupId;
                 task_affinity_unpin();
 
-                l_mirrorBaseAddr += (this_node * hrmor_base)/2;
+                l_mirrorBaseAddr += (this_node * hrmor_base);
 
             }