sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>

Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
diff --git a/sound/oss/midibuf.c b/sound/oss/midibuf.c
index 8f45cd9..701c762 100644
--- a/sound/oss/midibuf.c
+++ b/sound/oss/midibuf.c
@@ -16,6 +16,8 @@
 #include <linux/stddef.h>
 #include <linux/kmod.h>
 #include <linux/spinlock.h>
+#include <linux/sched/signal.h>
+
 #define MIDIBUF_C
 
 #include "sound_config.h"