Fix board

Author: Jason2866

boards/airm2m_core_esp32c3.json

@@ -1,15 +1,13 @@
 {
   "build": {
-    "arduino":{
-      "ldscript": "esp32c3_out.ld"
-    },
     "core": "esp32",
     "f_cpu": "160000000L",
     "f_flash": "80000000L",
     "flash_mode": "dio",
     "extra_flags": [
       "-DARDUINO_AirM2M_CORE_ESP32C3",
-      "-DARDUINO_USB_MODE=1"
+      "-DARDUINO_USB_MODE=1",
+      "-DARDUINO_USB_CDC_ON_BOOT=1"
     ],
     "mcu": "esp32c3",
     "variant": "AirM2M_CORE_ESP32C3"