pseries: Enable HPT resizing for 2.10

We've now implemented a PAPR extensions which allows PAPR guests (i.e.
"pseries" machine type) to resize their hash page table during runtime.

However, that extension is only enabled if explicitly chosen on the
command line.  This patch enables it by default for spapr-2.10, but leaves
it disabled (by default) for older machine types.
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>
Reviewed-by: NLaurent Vivier <lvivier@redhat.com>

hw/ppc/spapr.c

@@ -3433,7 +3433,7 @@ static void spapr_machine_class_init(ObjectClass *oc, void *data)
     smc->dr_lmb_enabled = true;
     smc->tcg_default_cpu = "POWER8";
     mc->has_hotpluggable_cpus = true;
-    smc->resize_hpt_default = SPAPR_RESIZE_HPT_DISABLED;
+    smc->resize_hpt_default = SPAPR_RESIZE_HPT_ENABLED;
     fwc->get_dev_path = spapr_get_fw_dev_path;
     nc->nmi_monitor_handler = spapr_nmi;
     smc->phb_placement = spapr_phb_placement;
@@ -3540,6 +3540,7 @@ static void spapr_machine_2_9_class_options(MachineClass *mc)
     SET_MACHINE_COMPAT(mc, SPAPR_COMPAT_2_9);
     mc->numa_auto_assign_ram = numa_legacy_auto_assign_ram;
     smc->pre_2_10_has_unused_icps = true;
+    smc->resize_hpt_default = SPAPR_RESIZE_HPT_DISABLED;
 }
 
 DEFINE_SPAPR_MACHINE(2_9, "2.9", false);