workqueue: rename kernel/workqueue_sched.h to kernel/workqueue_internal.h

Workqueue wants to expose more interface internal to kernel/.  Instead
of adding a new header file, repurpose kernel/workqueue_sched.h.
Rename it to workqueue_internal.h and add include protector.

This patch doesn't introduce any functional changes.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
diff --git a/kernel/workqueue_internal.h b/kernel/workqueue_internal.h
new file mode 100644
index 0000000..b3ea6ad
--- /dev/null
+++ b/kernel/workqueue_internal.h
@@ -0,0 +1,18 @@
+/*
+ * kernel/workqueue_internal.h
+ *
+ * Workqueue internal header file.  Only to be included by workqueue and
+ * core kernel subsystems.
+ */
+#ifndef _KERNEL_WORKQUEUE_INTERNAL_H
+#define _KERNEL_WORKQUEUE_INTERNAL_H
+
+/*
+ * Scheduler hooks for concurrency managed workqueue.  Only to be used from
+ * sched.c and workqueue.c.
+ */
+void wq_worker_waking_up(struct task_struct *task, unsigned int cpu);
+struct task_struct *wq_worker_sleeping(struct task_struct *task,
+				       unsigned int cpu);
+
+#endif /* _KERNEL_WORKQUEUE_INTERNAL_H */