SMF: Defined new attribute to store unsecure HOMER's base address.

Change-Id: Ic52eb9326f66a3443e78662811d17611ec4ecbd1
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/69515
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: PPE CI <ppe-ci+hostboot@us.ibm.com>
Tested-by: HWSV CI <hwsv-ci+hostboot@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: Gregory S. Still <stillgs@us.ibm.com>
Reviewed-by: RAHUL BATRA <rbatra@us.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/69520
Reviewed-by: RAJA DAS <rajadas2@in.ibm.com>

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

@@ -2254,4 +2254,20 @@
     <default>TRUE</default>
   </attribute>
   <!-- ********************************************************************* -->
+  <attribute>
+    <id>ATTR_UNSECURE_HOMER_ADDRESS</id>
+    <targetType>TARGET_TYPE_PROC_CHIP</targetType>
+    <description>Address is allocated by hostboot and HBRT and is populated 
+    by p9_hcode_image_build with sc2 instruction. It enables CME to invoke
+    a transition from HV to UV during STOP entry on an SMF enabled system.
+    Address value should be aligned with 2MB boundary.
+
+    Producer: Initialized by Hostboot firmware based on platform support
+    Consumers: Read by p9_hcode_image_build.C
+    </description>
+    <valueType>uint64</valueType>
+    <writeable/>
+    <initToZero/>
+  </attribute>
+  <!-- ********************************************************************* -->
 </attributes>