Add new istep for Hostboot done

Add a specific 'istep' MAGIC call that indicates a successful boot
that can be used by the Simics CI suite

Change-Id: If4dcdd7f16d8b630b0200d7d5edc61f473e4e123
Reviewed-on: http://rchgit01.rchland.ibm.com/gerrit1/69580
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: Daniel M. Crowell <dcrowell@us.ibm.com>

src/kernel/misc.C

@@ -107,6 +107,8 @@ namespace KernelMisc
                 if (c->master)
                 {
                     printk("No payload... nap'ing all threads.\n");
+                    // Let Simics know that we booted successfully
+                    MAGIC_INST_PRINT_ISTEP(0xFF,0xFF);
                 }
 
                 // Clear LPCR values that wakes up from nap.  LPCR[49, 50, 51]