Blackfin: br4: new board port

This adds support for the BR4 Appliance.  It is a quad channel ISDN BRI
board based on Blackfin BF537 CPU.

Signed-off-by: Dimitar Penev <dpn@switchfin.org>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/boards.cfg b/boards.cfg
index fd8db61..f320985 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -280,6 +280,7 @@
 bf561-ezkit                  blackfin    blackfin
 blackstamp                   blackfin    blackfin
 blackvme                     blackfin    blackfin
+br4                          blackfin    blackfin
 cm-bf527                     blackfin    blackfin
 cm-bf533                     blackfin    blackfin
 cm-bf537e                    blackfin    blackfin