Cleanup: remove redundant deleting on *~ files

Signed-off-by: Wolfgang Denk <wd@denx.de>
diff --git a/board/davinci/sonata/Makefile b/board/davinci/sonata/Makefile
index c58cd24..579efe2 100644
--- a/board/davinci/sonata/Makefile
+++ b/board/davinci/sonata/Makefile
@@ -41,7 +41,7 @@
 	rm -f $(SOBJS) $(OBJS)
 
 distclean:	clean
-	rm -f $(LIB) core *.bak *~ $(obj).depend
+	rm -f $(LIB) core *.bak $(obj).depend
 
 #########################################################################
 # This is for $(obj).depend target