evl/thread: remove the repeated inclusion of sched.h

This is a tiny fix for the repeated evl/sched.h inclusion.
Signed-off-by: lio <liu.hailong6@zte.com.cn>

kernel/evl/thread.c

@@ -31,7 +31,6 @@
 #include <evl/assert.h>
 #include <evl/lock.h>
 #include <evl/thread.h>
-#include <evl/sched.h>
 #include <evl/memory.h>
 #include <evl/file.h>
 #include <evl/factory.h>