NUCLEO_L496ZG add mbedOS 2 compatibility

Author: pmancele

targets/targets.json

@@ -3389,7 +3389,7 @@
         "detect_code": ["0823"],
         "macros": ["TRANSACTION_QUEUE_SIZE_SPI=2"],
         "device_has": ["ANALOGIN", "ANALOGOUT", "CAN", "I2C", "I2CSLAVE", "I2C_ASYNCH", "INTERRUPTIN", "LOWPOWERTIMER", "PORTIN", "PORTINOUT", "PORTOUT", "PWMOUT", "RTC", "SERIAL", "SERIAL_ASYNCH", "SERIAL_FC", "SLEEP", "SPI", "SPISLAVE", "SPI_ASYNCH", "STDIO_MESSAGES", "TRNG", "FLASH"],
-        "release_versions": ["5"],
+        "release_versions": ["2", "5"],
         "device_name": "STM32L496ZG"
     },
     "VBLUNO52": {