[SCSI] aacraid: better sysfs adapter information

Received from Mark Salyzyn.

Provide more accurate adapter information.

Allows the Adapter Firmware to override the Adapter product
information.

Signed-off-by: Mark Haverkamp <markh@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>