fw/runtime_config: Fix case where no available gov for cpu
fw/runtime_config: Fix case where no available gov for cpu

Ensure there is a default iterable value in the case there is no
governor entry for a particular cpu.

ARM-software/workload-automation,setrofim/workload-automation,setrofim/workload-automation,ARM-software/workload-automation,ARM-software/workload-automation,setrofim/workload-automation,setrofim/workload-automation,ARM-software/workload-automation