ESP32: Initial sort variants by platform (#7340)

variants/esp32/betafpv_900_tx_nano/platformio.ini

@@ -0,0 +1,17 @@
+[env:betafpv_900_tx_nano]
+extends = esp32_base
+board = esp32doit-devkit-v1
+board_level = extra
+build_flags =
+  ${esp32_base.build_flags}
+  -D BETAFPV_900_TX_NANO
+  -D VTABLES_IN_FLASH=1
+  -D CONFIG_DISABLE_HAL_LOCKS=1
+  -O2
+  -I variants/esp32/betafpv_900_tx_nano
+board_build.f_cpu = 240000000L
+upload_protocol = esptool
+;upload_port = /dev/ttyUSB0
+upload_speed = 460800
+lib_deps =
+  ${esp32_base.lib_deps}

variants/esp32/betafpv_900_tx_nano/variant.h

@@ -0,0 +1,28 @@
+// https://betafpv.com/products/elrs-nano-tx-module
+
+// no screen
+#define HAS_SCREEN 0
+
+// NO GPS
+#undef GPS_RX_PIN
+#undef GPS_TX_PIN
+
+#define USE_RF95
+
+#define LORA_SCK 18
+#define LORA_MISO 19
+#define LORA_MOSI 23
+#define LORA_CS 5
+
+#define LORA_DIO0 4
+#define LORA_RESET 14
+#define LORA_DIO1 2
+#define LORA_DIO2
+#define LORA_DIO3
+
+#define LED_PIN 16 // green - blue is at 17
+
+#define BUTTON_PIN 25
+#define BUTTON_NEED_PULLUP
+
+#undef EXT_NOTIFY_OUT