cpufreq: schedutil: make kobj_type structure constant

Since commit ee6d3dd4 ("driver core: make kobj_type constant.")
the driver core allows the usage of const struct kobj_type.

Take advantage of this to constify the structure definition to prevent
modification at runtime.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

kernel/sched/cpufreq_schedutil.c

@@ -546,7 +546,7 @@ static void sugov_tunables_free(struct kobject *kobj)
 	kfree(to_sugov_tunables(attr_set));
 }
 
-static struct kobj_type sugov_tunables_ktype = {
+static const struct kobj_type sugov_tunables_ktype = {
 	.default_groups = sugov_groups,
 	.sysfs_ops = &governor_sysfs_ops,
 	.release = &sugov_tunables_free,