sched/headers: Prepare to remove the <linux/mm_types.h> dependency from <linux/sched.h>

Update code that relied on sched.h including various MM types for them.

This will allow us to remove the <linux/mm_types.h> include from <linux/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>

arch/x86/entry/vsyscall/vsyscall_64.c

@@ -28,6 +28,7 @@
 #include <linux/kernel.h>
 #include <linux/timer.h>
 #include <linux/sched/signal.h>
+#include <linux/mm_types.h>
 #include <linux/syscalls.h>
 #include <linux/ratelimit.h>