aoechr: Convert from class_device to device

Signed-off-by: Tony Jones <tonyj@suse.de>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Sam Hopkins <sah@coraid.com>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>