Add Zephyr support for the Nucleo L552ZE-Q (#861)

Author: wymcg

boards/nucleo_l552ze_q.json

@@ -26,7 +26,8 @@
   "frameworks": [
     "arduino",
     "cmsis",
-    "stm32cube"
+    "stm32cube", 
+    "zephyr"
   ],
   "name": "ST Nucleo L552ZE-Q",
   "upload": {