Fix env:mks_robin_nano35 (#18516)

platformio.ini

@@ -552,6 +552,16 @@ extra_scripts = buildroot/share/PlatformIO/scripts/mks_robin_nano.py
 build_flags   = ${common_stm32f1.build_flags}
   -DMCU_STM32F103VE -DSS_TIMER=4
 
+#
+# MKS Robin Nano (STM32F103VET6) - MKS UI (LVGL)
+#
+[env:mks_robin_nano35]
+platform      = ${common_stm32f1.platform}
+extends       = env:mks_robin_nano
+extra_scripts = buildroot/share/PlatformIO/scripts/mks_robin_nano35.py
+lib_deps      = ${common_stm32f1.lib_deps}
+  MKS-LittlevGL=https://github.com/makerbase-mks/MKS-LittlevGL/archive/master.zip
+
 #
 # MKS Robin (STM32F103ZET6)
 #
@@ -627,23 +637,6 @@ build_flags   = ${common_stm32f1.build_flags}
 lib_ignore    = ${common_stm32f1.lib_ignore}
   LiquidCrystal, LiquidTWI2, TMCStepper, U8glib-HAL, SoftwareSerialM
 
-#
-# MKS Robin Nano (STM32F103VET6) - MKS UI (LVGL)
-#
-[env:mks_robin_nano35]
-platform      = ststm32
-board         = genericSTM32F103VE
-platform_packages = tool-stm32duino
-build_flags   = !python Marlin/src/HAL/STM32F1/build_flags.py
-  ${common.build_flags} -std=gnu++14 -DHAVE_SW_SERIAL -DSS_TIMER=4
-build_unflags = -std=gnu++11
-extra_scripts = buildroot/share/PlatformIO/scripts/mks_robin_nano35.py
-src_filter    = ${common.default_src_filter} +<src/HAL/STM32F1>
-lib_deps      = ${common.lib_deps}
-  SoftwareSerialM
-  MKS-LittlevGL=https://github.com/makerbase-mks/MKS-LittlevGL/archive/master.zip
-lib_ignore    = Adafruit NeoPixel, SPI
-
 #
 # Malyan M200 v2 (STM32F070RB)
 #