Only save the CME FIR Masks after they have been setup once

Making the CME FIR path follow the same logic as the other PM
FIRs with regards to doing save/restore of the masks.

Also added an enumeration for the attribute that controls things
to make the code easier to read.

Change-Id: I2f9eabec4cb036ec9f79da07143f18fe18ee5747
CQ: SW448193
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/67668
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: HWSV CI <hwsv-ci+hostboot@us.ibm.com>
Tested-by: PPE CI <ppe-ci+hostboot@us.ibm.com>
Tested-by: Hostboot CI <hostboot-ci+hostboot@us.ibm.com>
Reviewed-by: Daniel M. Crowell <dcrowell@us.ibm.com>
Reviewed-by: Jennifer A Stofer <stofer@us.ibm.com>
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/68395
Reviewed-by: Sachin Gupta <sgupta2m@in.ibm.com>

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

@@ -111,6 +111,7 @@
       <valueType>uint8</valueType>
       <initToZero/>
       <writeable/>
+      <enum>NO_INIT=0, FIRS_INITED=1, FIRS_INITED_IN_RESET=2</enum>
   </attribute>
   <!-- ********************************************************************* -->
   <attribute>