[Wio 3G] Added default I/F type and pin defs

Author: ytsuboi

targets/TARGET_STM/TARGET_STM32F4/TARGET_STM32F439xI/TARGET_WIO_3G/PinNames.h

@@ -168,6 +168,8 @@ typedef enum {
     // Grove connector namings
     D38         = PC_6,
     D39         = PC_7,
+    D19         = PB_3,
+    D20         = PB_4,
     A4          = PA_4,
     A5          = PA_5,
     A6          = PA_6,

targets/targets.json

@@ -3166,8 +3166,11 @@
         ],
         "detect_code": ["9014"],
         "release_versions": ["2", "5"],
-        "device_name": "STM32F439VI",
-        "bootloader_supported": true
+        "device_name" : "STM32F439VI",
+        "bootloader_supported": true,
+        "overrides": {
+            "network-default-interface-type": "CELLULAR"
+        }
     },
     "DISCO_F051R8": {
         "inherits": ["FAMILY_STM32"],