[ppc4xx] Add initial lwmon5 board support

This patch adds initial support for the Liebherr lwmon5 board euqipped
with an AMCC 440EPx PowerPC.

Signed-off-by: Stefan Roese <sr@denx.de>
diff --git a/Makefile b/Makefile
index d5e220a..2d8cff3 100644
--- a/Makefile
+++ b/Makefile
@@ -1139,6 +1139,9 @@
 luan_config:	unconfig
 	@$(MKCONFIG) $(@:_config=) ppc ppc4xx luan amcc
 
+lwmon5_config:	unconfig
+	@$(MKCONFIG) $(@:_config=) ppc ppc4xx lwmon5
+
 METROBOX_config: unconfig
 	@$(MKCONFIG) $(@:_config=) ppc ppc4xx metrobox sandburst