[SCSI] qla2xxx: Update ISP24xx firwmare loading heuristics.

If firmware image is unavailable via request_firwmare(), then
attempt to load the image (likely out-of-date) stored in flash
memory.

Signed-off-by: Andrew Vasquez <andrew.vasquez@qlogic.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>