m32r: convert cpumask api

We plan to remove cpus_xx() old cpumask APIs later.  Also, we plan to
change mm_cpu_mask() implementation, allocate only nr_cpu_ids, thus
*mm_cpu_mask() is dangerous operation.

Then, this patch convert them.

Signed-off-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>