Don't clean folders without Makefile

Makefile

@@ -179,18 +179,20 @@ clean:
 		true; \
 	else \
 		for dir in $(SUBDIRS); do \
-			depth=$(MAKELEVEL); \
-			while [ $${depth} -gt 0 ] ; do \
-				echo -n " "; \
-				depth=`expr $$depth - 1`; \
-			done; \
-			echo " <$$dir>"; \
-			$(MAKE) -s -S -C $$dir $@ $(ARCH); \
-			while [ $${depth} -gt 0 ] ; do \
-				echo -n " "; \
-				depth=`expr $$depth - 1`; \
-			done; \
-			echo " </$$dir>"; \
+			if [ -e "$$dir/Makefile" ]; then \
+				depth=$(MAKELEVEL); \
+				while [ $${depth} -gt 0 ] ; do \
+					echo -n " "; \
+					depth=`expr $$depth - 1`; \
+				done; \
+				echo " <$$dir>"; \
+				$(MAKE) -s -S -C $$dir $@ $(ARCH); \
+				while [ $${depth} -gt 0 ] ; do \
+					echo -n " "; \
+					depth=`expr $$depth - 1`; \
+				done; \
+				echo " </$$dir>"; \
+			fi \
 		done; \
 		for target in $(TARGETS); do \
 			rm -f $$target.$(ARCH); \
@@ -210,18 +212,20 @@ cleandeps:
 		true; \
 	else \
 		for dir in $(SUBDIRS); do \
-			depth=$(MAKELEVEL); \
-			while [ $${depth} -gt 0 ] ; do \
-				echo -n " "; \
-				depth=`expr $$depth - 1`; \
-			done; \
-			echo " <$$dir>"; \
-			$(MAKE) -s -S -C $$dir $@ $(ARCH); \
-			while [ $${depth} -gt 0 ] ; do \
-				echo -n " "; \
-				depth=`expr $$depth - 1`; \
-			done; \
-			echo " </$$dir>"; \
+			if [ -e "$$dir/Makefile" ]; then \
+				depth=$(MAKELEVEL); \
+				while [ $${depth} -gt 0 ] ; do \
+					echo -n " "; \
+					depth=`expr $$depth - 1`; \
+				done; \
+				echo " <$$dir>"; \
+				$(MAKE) -s -S -C $$dir $@ $(ARCH); \
+				while [ $${depth} -gt 0 ] ; do \
+					echo -n " "; \
+					depth=`expr $$depth - 1`; \
+				done; \
+				echo " </$$dir>"; \
+			fi \
 		done; \
 		for target in $(TARGETS); do \
 			rm -f $$target.$(ARCH); \