DISCO_L475VG_IOT: Add ARDUINO in "supported_form_factor"

Author: bcostm

targets/targets.json

@@ -1324,9 +1324,10 @@
     "DISCO_L475VG_IOT": {
         "inherits": ["Target"],
         "core": "Cortex-M4F",
-        "default_toolchain": "ARM",
         "extra_labels": ["STM", "STM32L4", "STM32L475VG"],
         "supported_toolchains": ["ARM", "uARM", "IAR", "GCC_ARM"],
+        "default_toolchain": "ARM",
+        "supported_form_factors": ["ARDUINO"],
         "detect_code": ["0764"],
         "macros": ["TRANSACTION_QUEUE_SIZE_SPI=2", "USBHOST_OTHER"],
         "device_has": ["ANALOGIN", "ANALOGOUT", "CAN", "I2C", "I2CSLAVE", "I2C_ASYNCH", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "SPI_ASYNCH", "STDIO_MESSAGES", "TRNG"],