SoftwareSerialM for MEEB (#18178)

platformio.ini

                     -DGENERIC_BOOTLOADER
 extra_scripts     = pre:buildroot/share/PlatformIO/scripts/STM32F103RC_MEEB_3DP_create_variant.py
     buildroot/share/PlatformIO/scripts/STM32F103RC_MEEB_3DP.py
-lib_deps          = ${common.lib_deps}
+lib_deps          = ${common_stm32f1.lib_deps}
     USBComposite for STM32F1@==0.91
     Adafruit NeoPixel=https://github.com/ccccmagicboy/Adafruit_NeoPixel#meeb_3dp_use
 lib_ignore        = SPI, LiquidCrystal