Device-Clean Script for Audio

Audio devices are cleaned up with an audio-clean script. The script performs an AUDIO_DRAIN ioctl system call to flush the device, then an AUDIO_SETINFO ioctl system call command to reset the device configuration to default. In addition, the script retrieves the audio chip registers by using the AUDIOGETREG ioctl system call. Any registers that deviate from the default settings are reset by using the AUDIOSETREG ioctl system call.