sim:tests: Cleanup leftover otbn smoketest download code

Use the build-from-source binaries instead of downloading renode
archived artifacts.

Change-Id: Ia8ddade7ef3d3ae15491561b0d249bc7803486a4
diff --git a/opentitan_peripherals_test.robot b/opentitan_peripherals_test.robot
index 6e669e5..25dde44 100644
--- a/opentitan_peripherals_test.robot
+++ b/opentitan_peripherals_test.robot
@@ -289,7 +289,7 @@
 
 Should Pass OTBN Simple Smoketest Test
     Create Log Tester               3
-    Execute Command                 include @scripts/single-node/opentitan-earlgrey.resc
+    Setup Machine
     Execute Command                 sysbus.otbn FixedRandomPattern "0xAAAAAAAA99999999AAAAAAAA99999999AAAAAAAA99999999AAAAAAAA99999999"
     Execute Command                 sysbus.otbn KeyShare0 "0xDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEFDEADBEEF"
     Execute Command                 sysbus.otbn KeyShare1 "0xBAADF00DBAADF00DBAADF00DBAADF00DBAADF00DBAADF00DBAADF00DBAADF00DBAADF00DBAADF00DBAADF00DBAADF00D"