Fixing width cast warnings that pop-up when running with NUM_CORES > 1

[Ciprian167]

test_l2_cache.sv - Adding explicit comparison for l2i_request_valid, as for NUM_CORES > 1, its width will be greater than 1 bit.

test_control_registers.sv - Removing fixed width cast on cr_suspend_thread and cr_resume_thread asserts, since their size will change based on NUM_CORES.

[jbush001]

Thanks!