platformio.ini updates for HUB75

* -D WLEDMM_SLOWPATH prevents using I2S#1 for ws281x leds
- matrixPortal S3: minor update to use more PSRAM (and keep more RAM availeable)

platformio.ini

@@ -1071,6 +1071,7 @@ HUB75_build_flags =
   -D NO_FAST_FUNCTIONS ;; If you are not using AdafruitGFX than you probably do not need this either, save memory/code size
   -D NO_CIE1931 ;; Do not use LED brightness compensation described in CIE 1931. We use FastLED dimming already
   -D S3_LCD_DIV_NUM=20 ;; Attempt to fix wifi performance issue when panel active with S3 chips
+  -D WLEDMM_SLOWPATH   ;; WLEDMM: do not use I2S for driving ws2812 LEDs (HUB75 driver needs I2S#1)
 HUB75_lib_deps = https://github.com/mrcodetastic/ESP32-HUB75-MatrixPanel-DMA.git#aa28e2a9 ;; S3_LCD_DIV_NUM fix
 HUB75_lib_ignore = ESP32 HUB75 LED MATRIX PANEL DMA Display ;; to remove the HUB75 lib dependancy (saves a few bytes)
 
@@ -2667,6 +2668,8 @@ build_flags = ${common.build_flags} ${esp32s3.build_flags} -Wno-misleading-inden
   -D LOLIN_WIFI_FIX ;; try this in case Wifi does not work
   -D WLED_WATCHDOG_TIMEOUT=0 -D CONFIG_ASYNC_TCP_USE_WDT=0
   -D WLED_USE_PSRAM -DBOARD_HAS_PSRAM ; tells WLED that PSRAM shall be used
+  -D WLED_USE_PSRAM_JSON -DALL_JSON_TO_PSRAM ; WLEDMM --> force all JSON stuff into PSRAM; gives more free heap
+  ; -DCONFIG_MBEDTLS_DYNAMIC_BUFFER=1 ;; optional - seems to move more buffers into PSRAM
   ${common_mm.HUB75_build_flags}
   -D DEFAULT_LED_TYPE=101
 lib_deps = ${esp32s3.lib_deps} ${common_mm.lib_deps_S} ;; ;;  do not include ${esp32.lib_depsV4} !!!!