Add espressif esp32-c6-devkitm-1 board (platformio#1173)

Author: Jason2866

boards/esp32-c6-devkitm-1.json

@@ -0,0 +1,29 @@
+{
+  "build": {
+    "core": "esp32",
+    "f_cpu": "160000000L",
+    "f_flash": "80000000L",
+    "flash_mode": "qio",
+    "mcu": "esp32c6",
+    "variant": "esp32c6"
+  },
+  "connectivity": [
+    "wifi"
+  ],
+  "debug": {
+    "openocd_target": "esp32c6.cfg"
+  },
+  "frameworks": [
+    "espidf"
+  ],
+  "name": "Espressif ESP32-C6-DevKitM-1",
+  "upload": {
+    "flash_size": "4MB",
+    "maximum_ram_size": 327680,
+    "maximum_size": 4194304,
+    "require_upload_port": true,
+    "speed": 460800
+  },
+  "url": "https://docs.espressif.com/projects/espressif-esp-dev-kits/en/latest/esp32c6/esp32-c6-devkitm-1/index.html",
+  "vendor": "Espressif"
+}