Blackfin: support console-over-JTAG

The Blackfin JTAG has the ability to pass data via a back-channel without
halting the processor.  Utilize that channel to emulate a console.

Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/include/devices.h b/include/devices.h
index 20ddfc4..84c4514 100644
--- a/include/devices.h
+++ b/include/devices.h
@@ -116,5 +116,8 @@
 #ifdef CONFIG_NETCONSOLE
 int	drv_nc_init (void);
 #endif
+#ifdef CONFIG_JTAG_CONSOLE
+int drv_jtag_console_init (void);
+#endif
 
 #endif	/* _DEVICES_H_ */