posix: add pthread_mutex_timedlock's declaration, fix
[Detail]
add pthread_mutex_timedlock's declaration
[Verified Cases]
Build Pass: <py_engine_demo>
Test Pass:  <py_engine_demo>
@@ -149,6 +149,7 @@ int pthread_mutex_destroy(pthread_mutex_t *mutex);
int pthread_mutex_lock(pthread_mutex_t *mutex);
int pthread_mutex_unlock(pthread_mutex_t *mutex);
int pthread_mutex_trylock(pthread_mutex_t *mutex);
+int pthread_mutex_timedlock(pthread_mutex_t *mutex, const struct timespec *at);
int pthread_mutex_getprioceiling(const pthread_mutex_t *__restrict mutex, int *__restrict prioceiling);
int pthread_mutex_setprioceiling(pthread_mutex_t *__restrict mutex, int prioceiling, int *__restrict old_ceiling);
