Makefile: use public timing-scripts-repo url
diff --git a/Makefile b/Makefile
index 1ccd574..0d38dd5 100644
--- a/Makefile
+++ b/Makefile
@@ -260,7 +260,7 @@
 export CUP_ROOT=$(shell pwd)
 export TIMING_ROOT?=$(shell pwd)/deps/timing-scripts
 export PROJECT_ROOT=$(CUP_ROOT)
-timing-scripts-repo=git@github.com:efabless/timing-scripts.git
+timing-scripts-repo=https://github.com/efabless/timing-scripts.git
 
 $(TIMING_ROOT):
 	@mkdir -p $(CUP_ROOT)/deps