Cleanup from Axone targeting base commit

In the commit where new Axone targets were added there was some
minor unadressed comments. This commit updates the override tool
to use the correct short name for mem_port ( "mp" ) and corrects
an alignment error in attribute_types.xml

Change-Id: Idc0b2e32869ed91d88d0a71aae63a7dddd03f387
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/64867
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: William G. Hoffa <wghoffa@us.ibm.com>

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

@@ -5095,7 +5095,7 @@
         <name>OCMB_CHIP</name>
         <value>75</value>
     </enumerator>    <enumerator>
-    <name>MEM_PORT</name>
+        <name>MEM_PORT</name>
         <value>76</value>
     </enumerator>
     <enumerator>