Make ATTR_IO_OBUS_DCCAL_FLAGS initToZero

Change-Id: I6fb9b0c0f37e0867d34d01db303e45ebbaed93f6
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/41372
Dev-Ready: Matt K. Light <mklight@us.ibm.com>
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Reviewed-by: Matt K. Light <mklight@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: Sachin Gupta <sgupta2m@in.ibm.com>
Reviewed-by: Jennifer A. Stofer <stofer@us.ibm.com>
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/41379
Reviewed-by: Hostboot Team <hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Tested-by: FSP CI Jenkins <fsp-CI-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP HW <op-hw-jenkins+hostboot@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

src/import/chips/p9/procedures/xml/attribute_info/p9_io_obus_attributes.xml

@@ -37,6 +37,7 @@
     RX = 0x2
   </enum>
   <writeable/>
+  <initToZero/>
 </attribute>
 <!-- ********************************************************************** -->
 <attribute>