sched/headers: Prepare for new header dependencies before moving code to <uapi/linux/sched/types.h>

We are going to move scheduler ABI details to <uapi/linux/sched/types.h>,
which will be used from a number of .c files.

Create empty placeholder header that maps to <linux/types.h>.

Include the new header in the files that are going to need it.

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/drivers/firmware/psci_checker.c b/drivers/firmware/psci_checker.c
index 29d58fe..6523ce9 100644
--- a/drivers/firmware/psci_checker.c
+++ b/drivers/firmware/psci_checker.c
@@ -20,6 +20,7 @@
 #include <linux/cpu_pm.h>
 #include <linux/kernel.h>
 #include <linux/kthread.h>
+#include <uapi/linux/sched/types.h>
 #include <linux/module.h>
 #include <linux/preempt.h>
 #include <linux/psci.h>