[dv] Fix bad reference to instr_req_out
[dv] Fix bad reference to instr_req_out

instr_req_out no longer exists now PMP is handled on the IF/ID
interface.

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