Enable Resonant Clock

 -Was manually disabled in Hostboot due to issue
 -This commit removes the manual disable and allows XML to control

Change-Id: I991fd7619e957f0c663a025960ed447d9bbde7bf
RTC:176627
Reviewed-on: http://ralgit01.raleigh.ibm.com/gerrit1/46682
Tested-by: Jenkins Server <pfd-jenkins+hostboot@us.ibm.com>
Tested-by: Jenkins OP Build CI <op-jenkins+hostboot@us.ibm.com>
Reviewed-by: Christian R. Geddes <crgeddes@us.ibm.com>
Reviewed-by: William G. Hoffa <wghoffa@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: Daniel M. Crowell <dcrowell@us.ibm.com>

src/usr/isteps/istep15/host_build_stop_image.C

@@ -382,10 +382,6 @@ void* host_build_stop_image (void *io_pArgs)
         TARGETING::targetService().getTopLevelTarget(l_sys);
         assert( l_sys != NULL );
 
-        // @todo RTC:176627 Remove workaround setting SYSTEM_RESCLK_DISABLE
-        l_sys->setAttr<TARGETING::ATTR_SYSTEM_RESCLK_DISABLE>(0x1);
-        // end workaround
-
         if (l_sys->getAttr<TARGETING::ATTR_IS_MPIPL_HB>())
         {
             l_errl = HBPM::resetPMAll();

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

@@ -527,12 +527,6 @@
           <default>0x40000</default>
      </attribute>
 
-    <attribute>
-          <id>ATTR_SYSTEM_RESCLK_DISABLE</id>
-          <default>0x00</default>
-          <writeable/>
-    </attribute>
-
     <attribute>
           <id>ATTR_BACKUP_SEEPROM_SELECT</id>
           <writeable/>