signals: Prepare to split out <linux/signal_types.h> from <linux/signal.h>

Introduce dummy header and add dependencies to places that will depend on it.
Acked-by: NLinus 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: NIngo Molnar <mingo@kernel.org>

arch/mips/include/asm/abi.h

@@ -9,6 +9,8 @@
 #ifndef _ASM_ABI_H
 #define _ASM_ABI_H
 
+#include <linux/signal_types.h>
+
 #include <asm/signal.h>
 #include <asm/siginfo.h>
 #include <asm/vdso.h>

include/linux/signal.h

 #ifndef _LINUX_SIGNAL_H
 #define _LINUX_SIGNAL_H
 
-#include <linux/list.h>
 #include <linux/bug.h>
-#include <uapi/linux/signal.h>
+#include <linux/signal_types.h>
 
 struct task_struct;
 

include/linux/signal_types.h

+#ifndef _LINUX_SIGNAL_TYPES_H
+#define _LINUX_SIGNAL_TYPES_H
+
+#include <linux/list.h>
+#include <uapi/linux/signal.h>
+
+#endif /* _LINUX_SIGNAL_TYPES_H */