扩展了与进程策略设置相关的函数

Signed-off-by: caifuzhou <504631861@qq.com>

porting/linux/user/src/sched/sched_getscheduler.c

 #include <sched.h>
 #include <errno.h>
-#include <string.h>
 #include "syscall.h"
 
 int sched_getscheduler(pid_t pid)

porting/linux/user/src/sched/sched_setparam.c

 #include <sched.h>
 #include <errno.h>
-#include <string.h>
 #include "syscall.h"
 
 int sched_setparam(pid_t pid, const struct sched_param *param)