cciss: Consolidate duplicate bits in cciss_cmd.h & cciss_ioctl.h

There are several duplicate definitions in cciss_cmd.h and cciss_ioctl.h.
Consolidate these into the new cciss_defs.h file. This patch doesn't change
the definitions exposed under include/linux, so userspace apps shouldn't
be affected.

Acked-by: Stephen M. Cameron <scameron@beardog.cce.hp.com>
Signed-off-by: dann frazier <dannf@hp.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>