Cleanup out-or-tree building for some boards (.depend)

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/board/freescale/mpc8568mds/Makefile b/board/freescale/mpc8568mds/Makefile
index 8294d3b..ecdc4d3 100644
--- a/board/freescale/mpc8568mds/Makefile
+++ b/board/freescale/mpc8568mds/Makefile
@@ -39,7 +39,7 @@
 	rm -f $(OBJS) $(SOBJS)
 
 distclean:	clean
-	rm -f $(LIB) core *.bak .depend
+	rm -f $(LIB) core *.bak $(obj).depend
 
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