…ew rxaudiostats parameter to simpleusb.conf, which enables a new function check_rx_audio() in chan_simpleusb.c to be called during processing of received USB audio frames. If ADC clipping is then detected GPIO4 is set for 500mS to support illumination of a node / audio interface Clip LED. Statistics collected also include peak and average RMS audio levels averaged over the previous 1 second, which can be displayed from the simpleusb-tune-menu 'R' option or AMI 'susb tune menu-support a' function.

…' prefix to function names. Change rxaudiostats conf parameter name to 'checkrxaudio' and type to int, with value indicating GPIO# to use (or 0 to disable feature), validate value in hidhdwconfig()

…. Update susb tune-menu options to be consistent with that of usbradio. Default checkrxaudio conf param to off for usbradio. Add 'TBR' comments on some old sections of code that are present in both chan_simpleusb.c and chan_usbradio.c that will cause digital clipping of tx audio.

…O pin to use for the ADC Clip Detect Feature (0=disabled)). Set default value of clipledgpio to disabled in chan_[simpleusb|usbradio].c (so writing to a GPIO won't be automatically enabled during ASL updates), but enabled in configs/rpt/simpleusb.conf.

…raw Tx audio by 1.1 and (usbradio only) scales raw Rx audio by 0.8. (This code should marked TBR should be removed asap as described in issue AllStarLink#399.) Move call to check_rx_audio() to above where the 0.8 rx audio scaling is done in chan_usbradio.c.

…stats() per review comment

…arify that it will print using ast_verbose() if passed in fd < 0

…scaling/clipping code to remain unchanged for existing installs or if user enables parameter in simpleusb/usbradio .conf.