Upgrade include/asm-m32r/atomic.h.

* include/asm-m32r/atomic.h

- Change atomic_add(), atomic_sub(), atomic_inc() and atomic_dec() from
  function to macro.

- Change not to use fixed woking register in atomic_clear_mask() and
  atomic_set_mask().

- Update comments: "return" to "return it", and so on.
Signed-off-by: Hirokazu Takata <takata@linux-m32r.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>