cpufreq: loongson2: Remove unused linux/sched.h headers

Since commit 759f534e(CPUFREQ: Loongson2: drop set_cpus_allowed_ptr()),
the header <linux/sched.h> is useless in oongson2_cpufreq.c, so remove it.
Signed-off-by: Hailong Liu <liu.hailong6@zte.com.cn>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/cpufreq/loongson2_cpufreq.c

@@ -16,7 +16,6 @@
 #include <linux/cpufreq.h>
 #include <linux/module.h>
 #include <linux/err.h>
-#include <linux/sched.h>	/* set_cpus_allowed() */
 #include <linux/delay.h>
 #include <linux/platform_device.h>