[dv] Pass end_signature_addr to generate test step

The CSR test generation needs to know end_signature_addr. Previously
this wasn't being passed to the test generator so CSR tests just looped
forever.

dv/uvm/core_ibex/scripts/run-instr-gen.py

@@ -70,6 +70,7 @@ def main() -> int:
                 '--test', testname,
                 '--start_seed', str(seed),
                 '--iterations', '1',
+                '--end_signature_addr', args.end_signature_addr,
                 '--sim_opts', sim_opts_str,
                 '--debug', orig_list])