Added BusLogic BT-542B BIOS support (patch from TheCollector1995);

Brought the Adaptec AHA-1540B BIOS support to an essentially work state;
Fixed some warnings in CPU/808x.c.

src/cdrom.h

@@ -233,6 +233,7 @@ void cdrom_update_cdb(uint8_t *cdb, int lba_pos, int number_of_blocks);
 void cdrom_insert(uint8_t id);
 
 int find_cdrom_for_scsi_id(uint8_t scsi_id, uint8_t scsi_lun);
+int cdrom_read_capacity(uint8_t id, uint8_t *cdb, uint8_t *buffer, uint32_t *len);
 
 #define cdrom_sense_error cdrom[id].sense[0]
 #define cdrom_sense_key cdrom[id].sense[2]