[SCSI] qla4xxx: Use offset based on adapter type to set CHAP entry in flash

To write a CHAP entry in adapter's flash calculate the offset based
on the type of adapter.

Signed-off-by: Adheer Chandravanshi <adheer.chandravanshi@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>