[SCSI] ipr: Remove usage of pci driver data

Since ipr handles dynamic ids, it must handle driver_data
not being set, so remove the current usage of driver_data
so it can be used for other things in future patches.

Signed-off-by: Brian King <brking@linux.vnet.ibm.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>