IXP: Move PDNB3 and SCPU from Makefile to boards.cfg

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Bryan Hundven <bryanhundven@gmail.com>
Cc: Michael Schwingen <rincewind@discworld.dascon.de>
diff --git a/boards.cfg b/boards.cfg
index 28cc345..ade2034 100644
--- a/boards.cfg
+++ b/boards.cfg
@@ -244,6 +244,8 @@
 actux3                       arm         ixp
 actux4                       arm         ixp
 dvlhost                      arm         ixp
+pdnb3                        arm         ixp         pdnb3               prodrive
+scpu                         arm         ixp         pdnb3               prodrive       -           pdnb3:SCPU
 balloon3                     arm         pxa
 lubbock                      arm         pxa
 palmld                       arm         pxa