Add support for DFRobot FireBeetle 2 ESP32-E board (platformio#1026)

Author: lmarzen

boards/dfrobot_firebeetle2_esp32e.json

@@ -0,0 +1,39 @@
+{
+  "build": {
+    "arduino": {
+      "ldscript": "esp32_out.ld"
+    },
+    "core": "esp32",
+    "extra_flags": [
+      "-DARDUINO_DFROBOT_FIREBEETLE_2_ESP32E",
+      "-DARDUINO_RUNNING_CORE=1",
+      "-DARDUINO_EVENT_RUNNING_CORE=1"
+    ],
+    "f_cpu": "240000000L",
+    "f_flash": "40000000L",
+    "flash_mode": "dio",
+    "mcu": "esp32",
+    "variant": "dfrobot_firebeetle2_esp32e"
+  },
+  "connectivity": [
+    "wifi",
+    "bluetooth"
+  ],
+  "debug": {
+    "openocd_board": "esp-wroom-32.cfg"
+  },
+  "frameworks": [
+    "arduino",
+    "espidf"
+  ],
+  "name": "DFRobot Firebeetle 2 ESP32-E",
+  "upload": {
+    "flash_size": "4MB",
+    "maximum_ram_size": 327680,
+    "maximum_size": 4194304,
+    "require_upload_port": true,
+    "speed": 460800
+  },
+  "url": "https://wiki.dfrobot.com/FireBeetle_Board_ESP32_E_SKU_DFR0654",
+  "vendor": "DFRobot"
+}