[dv] Pass end_signature_addr to generate test step
[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.

AmbiML/ibex,lowRISC/ibex,AmbiML/ibex,AmbiML/ibex,lowRISC/ibex,lowRISC/ibex,AmbiML/ibex,lowRISC/ibex