kobject: export kobj_sysfs_ops

struct kobj_attribute implements the baseline attribute functionality
that can be used all over the place. We should export the ops associated
with it.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
Signed-off-by: Chris Mason <clm@fb.com>