updates for mdev PIO config

- updated mdev config, to use latest arduinoFFT, plus threadsafe LittleFS, plus default to 80Mhz flash speed.
- re-introducing the preset saving fix from SR WLED. Still I don't believe that upstream got that corrected properly.

platformio.ini

@@ -224,7 +224,9 @@ default_partitions = tools/WLED_ESP32_4MB_1MB_FS.csv
 
 lib_deps =
   ${env.lib_deps}
-  https://github.com/lorol/LITTLEFS.git
+  ; https://github.com/lorol/LITTLEFS.git
+  ; WLEDSR specific: use patched version of lorol LittleFS
+  https://github.com/softhack007/LITTLEFS-threadsafe.git#master
   makuna/NeoPixelBus @ 2.6.9
   https://github.com/pbolduc/AsyncTCP.git @ 1.2.0
 
@@ -449,14 +451,20 @@ platform = ${esp32.platform}
 upload_speed = 460800 ; or 921600
 platform_packages = ${esp32.platform_packages}
 build_unflags = ${common.build_unflags}
+
 build_flags = ${common.build_flags_esp32}
   -D WLED_RELEASE_NAME=ESP32 #-D WLED_DISABLE_BLYNK #-D WLED_DISABLE_BROWNOUT_DET
   -D USERMOD_AUDIOREACTIVE
+  -D UM_AUDIOREACTIVE_USE_NEW_FFT
   -D USERMOD_CUSTOMEFFECTS
+
 lib_deps = ${esp32.lib_deps}
-  https://github.com/blazoncek/arduinoFFT.git ; arduinoFFT @ 1.5.6
+  ; https://github.com/blazoncek/arduinoFFT.git ; arduinoFFT @ 1.5.6
+  https://github.com/kosme/arduinoFFT#develop @ 1.9.2
 monitor_filters = esp32_exception_decoder
 board_build.partitions = ${esp32.default_partitions}
+board_build.f_flash = 80000000L
+board_build.flash_mode = dio
 
 [env:esp8266mdev]
 extends = env:d1_mini