Fix compile of swim3 as module

The current pmac32_defconfig fails to build with the following error:

  Building modules, stage 2.
ERROR: "check_media_bay" [drivers/block/swim3.ko] undefined!
WARNING: modpost: Found 23 section mismatch(es).
To see full details build your kernel with:
'make CONFIG_DEBUG_SECTION_MISMATCH=y'
make[2]: *** [__modpost] Error 1

This patch fixes that.

Signed-off-by: Tony Breeds <tony@bakeyournoodle.com>
Acked-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Acked-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
Cc: Josh Boyer <jwboyer@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>