ESP32s3: Migrate variants to new structure (#7343)

variants/esp32s3/station-g2/platformio.ini

@@ -0,0 +1,21 @@
+[env:station-g2]
+extends = esp32s3_base
+board = station-g2
+board_check = true
+board_build.partitions = default_16MB.csv
+board_build.mcu = esp32s3
+upload_protocol = esptool
+;upload_port = /dev/ttyACM0
+upload_speed = 921600
+lib_deps =
+  ${esp32s3_base.lib_deps}
+build_unflags =
+  ${esp32s3_base.build_unflags}
+  -DARDUINO_USB_MODE=1
+build_flags = 
+  ${esp32s3_base.build_flags}
+  -D STATION_G2
+  -I variants/esp32s3/station-g2
+  -DBOARD_HAS_PSRAM
+  -DSTATION_G2
+  -DARDUINO_USB_MODE=0