sched/headers: Prepare to move cputime functionality from <linux/sched.h> into <linux/sched/cputime.h>

Introduce a trivial, mostly empty <linux/sched/cputime.h> header
to prepare for the moving of cputime functionality out of sched.h.

Update all code that relies on these facilities.

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/arch/x86/kvm/hyperv.c b/arch/x86/kvm/hyperv.c
index f701d44..ebae57a 100644
--- a/arch/x86/kvm/hyperv.c
+++ b/arch/x86/kvm/hyperv.c
@@ -28,6 +28,8 @@
 
 #include <linux/kvm_host.h>
 #include <linux/highmem.h>
+#include <linux/sched/cputime.h>
+
 #include <asm/apicdef.h>
 #include <trace/events/kvm.h>