RanjanThales

Results 2 issues of RanjanThales

### Is there an existing CVA6-SDK task for this? - [X] I have searched the existing task issues ### Task Description NA ### Description of Done NA

task

Added Simulation stop scenario and outputs signals tests_passed, tests_failed, exit_value, exit_valid to **cva6_tb.sv** and **cva6_core_tb_sram.sv**

DO NOT MERGE
cva6