forgot, there is no embedded HLE audio code in RA audio_plugin.c

I forgot that there is no HLE RSP audio processing code in core `mupen64plus-libretro`.  While the HLE RSP graphics (RDP/RSP) code is already handled within the Glide64, RiceVideo and glN64 modules, the libretro audio module is a direct interface to the libretro audio frontend and the N64 audio interface registers--in other words, it is LLE only.  The only HLE audio code is the stuff in the Mupen64 Hacktarux/Azimer HLE RSP plugin that bobby smiles contributed to.  If you use that plugin, then my CFG_HLE_AUD flag control is not even accessed; therefore there is no reason to set this flag to anything other than false, i.e., 0.