Add no_export tag to PROC_PCIE_NUM_PEC attribute

This attribute is being deleted but there were hwsv compile fails
when it was removed from HB. Until its removed we must make sure it
doesnt get exported

Change-Id: I3104f3f94d9d10b138e2213808a2967962fd024c
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/45789
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Reviewed-by: Matt Derksen <mderkse1@us.ibm.com>
Reviewed-by: Martin Gloff <mgloff@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>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>

src/usr/targeting/common/xmltohb/attribute_types.xml

@@ -6061,6 +6061,7 @@
   </simpleType>
   <persistency>non-volatile</persistency>
   <readable/>
+  <no_export/>
 </attribute>
 
 <attribute>