sched/headers: Move scheduler topology interfaces to <linux/sched/topology.h>

sched/headers: Move scheduler topology interfaces to <linux/sched/topology.h>

The vast majority of sched.h users does not require the topology types and
interfaces, so split them out into <linux/sched/topology.h>.

This reduces the size of linux/sched.h by ~6%.

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>