Update platformio.ini

Author: Jason2866

examples/espidf-arduino-h2zero-BLE_scan/platformio.ini

@@ -12,8 +12,6 @@
 platform = espressif32
 framework = arduino
 monitor_speed = 115200
-build_flags =
-    '-DCONFIG_BT_NIMBLE_EXT_ADV=1'
 lib_deps =
     https://github.com/h2zero/NimBLE-Arduino.git#nimble-1.6-c6-build-working
 lib_ignore =
@@ -35,3 +33,8 @@ custom_component_remove =
 
 [env:esp32]
 board = esp32dev
+
+[env:esp32c3]
+board = esp32-c3-devkitm-1
+build_flags =
+    '-DCONFIG_BT_NIMBLE_EXT_ADV=1'