scsi/ahci: add support for non-PCI controllers

Add support for AHCI controllers that are not PCI based.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Wolfgang Denk <wd@denx.de>
diff --git a/include/scsi.h b/include/scsi.h
index aaafc9c..c52759c 100644
--- a/include/scsi.h
+++ b/include/scsi.h
@@ -185,6 +185,7 @@
  * functions residing inside cmd_scsi.c
  */
 void scsi_init(void);
+void scsi_scan(int mode);
 
 
 #define SCSI_IDENTIFY					0xC0  /* not used */