DCA: convert struct class_device to struct device.

Thanks to Kay for keeping us honest.

Signed-off-by: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Cc: "Williams, Dan J" <dan.j.williams@intel.com>
Acked-by: Greg KH <greg@kroah.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>