Add attribute ATTR_EFF_RANK_GROUP_OVERRIDE

Change-Id: Ia0d9009f88ef65dac7469ac23eb41083444375f7
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/36508
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: STEPHEN GLANCY <sglancy@us.ibm.com>
Reviewed-by: Brian R. Silver <bsilver@us.ibm.com>
Reviewed-by: JACOB L. HARVEY <jlharvey@us.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/69799
Reviewed-by: Sachin Gupta <sgupta2m@in.ibm.com>
Tested-by: Sachin Gupta <sgupta2m@in.ibm.com>

src/import/chips/p9/procedures/xml/attribute_info/memory_mcs_attributes.xml

@@ -3127,4 +3127,21 @@
         <mssAccessorName>reorder_queue_setting</mssAccessorName>
     </attribute>
 
+    <attribute>
+        <id>ATTR_EFF_RANK_GROUP_OVERRIDE</id>
+        <targetType>TARGET_TYPE_MCS</targetType>
+        <description>
+          Override PHY RANK_PAIR settings. First uint16 value is for RANK_PAIR0
+          register value, and second is for RANK_PAIR1. Note that DIMM1 ranks in
+          a dual-drop config will be converted from Centaur canonical number
+          (4,5) to correct PHY settings (2,3). Set this attribute to zero
+          to use default settings.
+        </description>
+        <initToZero></initToZero>
+        <valueType>uint16</valueType>
+        <writeable/>
+        <array> 2 2 </array>
+        <mssAccessorName>eff_rank_group_override</mssAccessorName>
+    </attribute>
+
 </attributes>