framework/target: manager: use get_target_description
framework/target: manager: use get_target_description

use the new get_target_description() when initializing the target inside
TargetManager, instead of manually searching through results of
list_target_descriptions().

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