Change default cpufreq governor from performance to ondemand

Signed-off-by: Liu, Jinsong <jinsong.liu@intel.com>

diff -r 73683bc4534b xen/include/acpi/cpufreq/cpufreq.h
--- a/xen/include/acpi/cpufreq/cpufreq.h	Thu Dec 11 11:05:59 2008 +0800
+++ b/xen/include/acpi/cpufreq/cpufreq.h	Thu Dec 11 13:22:27 2008 +0800
@@ -93,7 +93,7 @@ extern int cpufreq_register_governor(str
 extern int cpufreq_register_governor(struct cpufreq_governor *governor);
 extern int cpufreq_unregister_governor(struct cpufreq_governor *governor);
 extern struct cpufreq_governor *__find_governor(const char *governor);
-#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_performance
+#define CPUFREQ_DEFAULT_GOVERNOR &cpufreq_gov_dbs
 
 /* pass a target to the cpufreq driver */
 extern int __cpufreq_driver_target(struct cpufreq_policy *policy,