build: fix make clean, delete package directories for selected arch

Signed-off-by: Felix Fietkau <[email protected]>

Makefile

@@ -51,7 +51,7 @@ printdb:
 prepare: $(target/stamp-compile)
 
 clean: FORCE
-	rm -rf $(BUILD_DIR) $(STAGING_DIR) $(BIN_DIR) $(BUILD_LOG_DIR)
+	rm -rf $(BUILD_DIR) $(STAGING_DIR) $(BIN_DIR) $(OUTPUT_DIR)/packages/$(ARCH_PACKAGES) $(BUILD_LOG_DIR)
 
 dirclean: clean
 	rm -rf $(STAGING_DIR_HOST) $(TOOLCHAIN_DIR) $(BUILD_DIR_HOST) $(BUILD_DIR_TOOLCHAIN)