framework/output: Speedup discover_wa_outputs()
framework/output: Speedup discover_wa_outputs()

Avoid recursing into subdirectory of folders containing __meta, since
they are not of interest and recursing can take a very large amount of
time if there are lot of files, like if there is a sysfs dump.

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