[SCSI] qla4xxx: Support setting of local CHAP index for flash target entry

Support setting of CHAP_OUT_IDX param for the target entry in flash.
Setting of valid local CHAP index with enable CHAP AUTH for that
flash target entry and disabling CHAP AUTH will invalidate the CHAP
index for the flash target entry.

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>