[libata] improve device scan
Replace SCSI's legacy "bang at the door" method of probing with one
directly controlled by the underlying ATA transport layer.
We now only call scsi_scan_target() for devices we find, rather than
probing every possible channel/id within a certain range.
diff --git a/drivers/scsi/libata.h b/drivers/scsi/libata.h
index d608b3a..c7a1fa1 100644
--- a/drivers/scsi/libata.h
+++ b/drivers/scsi/libata.h
@@ -51,6 +51,7 @@
/* libata-scsi.c */
+extern void ata_scsi_scan_host(struct ata_port *ap);
extern void ata_to_sense_error(struct ata_queued_cmd *qc, u8 drv_stat);
extern int ata_scsi_error(struct Scsi_Host *host);
extern unsigned int ata_scsiop_inq_std(struct ata_scsi_args *args, u8 *rbuf,