sched/headers: Move more mm_struct related functionality from <linux/sched.h> to...

sched/headers: Move more mm_struct related functionality from <linux/sched.h> to <linux/sched/mm.h>

Neither the mmap_layout nor the mm_update_next_owner() methods need to be
in <linux/sched.h> - move them to the more appropriate <linux/sched/mm.h> header.

Acked-by: Linus Torvalds <[email protected]>
Cc: Mike Galbraith <[email protected]>
Cc: Peter Zijlstra <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: [email protected]
Signed-off-by: Ingo Molnar <[email protected]>