add hwid for auto-detection (#2619)

boards/t-echo.json

@@ -7,7 +7,10 @@
     "cpu": "cortex-m4",
     "extra_flags": "-DARDUINO_NRF52840_TTGO_EINK -DNRF52840_XXAA",
     "f_cpu": "64000000L",
-    "hwids": [["0x239A", "0x4405"]],
+    "hwids": [
+      ["0x239A", "0x4405"],
+      ["0x239A", "0x002A"]
+    ],
     "usb_product": "TTGO_eink",
     "mcu": "nrf52840",
     "variant": "t-echo",