scsi: aic7xxx: Remove unused aic7770_find_device()

'aic7770_find_device()' has been unused since 2005's
  commit dedd8310 ("[SCSI] aic7xxx: remove Linux 2.4 ifdefs")

Remove it and the associated constant. (Whether anyone still has one of
these cards in use is another question, I've just build tested this).

Signed-off-by: Dr. David Alan Gilbert <linux@treblig.org>
Link: https://lore.kernel.org/r/20240913170116.250996-1-linux@treblig.org


Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>