[PATCH] sil24: add ATAPI support

This patch implements ATAPI support for sil24 and bumps driver version
to 0.23.

Signed-off-by: Tejun Heo <htejun@gmail.com>

--

Jeff, it has been converted to use ->dev_config as pointed out.
Signed-off-by: Jeff Garzik <jgarzik@pobox.com>