706 RX 端增加淡入淡出处理办法

#include "audio_digital_vol.h"

dvol_handle user_dvol = {
    .toggle = 1,
    .fade = 1,
    .vol = 0,
    .vol_max = 16384,
    .vol_fade = 0,
    .fade_step = 5,
    .vol_target = 16384,
};

u16 user_cnt_num = CONNECT_IGNORE_STEP;

    if(user_cnt_num > 0){
        user_cnt_num--;
        memset(in->data, 0x00, in->data_len);
    }else if(user_cnt_num == 0){
        audio_digital_vol_run(&user_dvol, in->data, in->data_len); ///增加淡入处理x
    }