dm: scsi: Add a device pointer to scan_exec(), scsi_bus_reset()

With driver model these functions need a device pointer. Add one even
when CONFIG_DM_SCSI is not defined. This avoids having ugly conditional
function prototypes, When CONFIG_DM_SCSI is not defined we can just ignore
the pointer.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/include/scsi.h b/include/scsi.h
index d2fa8a5..af07dbe 100644
--- a/include/scsi.h
+++ b/include/scsi.h
@@ -196,8 +196,8 @@
 void scsi_init(void);
 #endif
 
-int scsi_exec(struct scsi_cmd *pccb);
-void scsi_bus_reset(void);
+int scsi_exec(struct udevice *dev, struct scsi_cmd *pccb);
+int scsi_bus_reset(struct udevice *dev);
 
 /***************************************************************************
  * functions residing inside cmd_scsi.c