STM32F4 USB: enable USB Device in targets.json

tests-usb_device-basic are OK on the following platforms:

NUCLEO_F412ZG
NUCLEO_F413ZH
NUCLEO_F429ZI
NUCLEO_F446ZE
DISCO_F413ZH
DISCO_F469NI

Author: bcostm

targets/targets.json

@@ -2440,7 +2440,8 @@
             "SERIAL_FC",
             "TRNG",
             "FLASH",
-            "MPU"
+            "MPU",
+            "USBDEVICE"
         ],
         "release_versions": ["2", "5"],
         "device_name": "STM32F412ZG",
@@ -2570,7 +2571,8 @@
             "TRNG",
             "FLASH",
             "QSPI",
-            "MPU"
+            "MPU",
+            "USBDEVICE"
         ],
         "bootloader_supported": true,
         "release_versions": ["2", "5"],
@@ -2611,7 +2613,8 @@
             "SERIAL_FC",
             "TRNG",
             "FLASH",
-            "MPU"
+            "MPU",
+            "USBDEVICE"
         ],
         "bootloader_supported": true,
         "release_versions": ["2", "5"],
@@ -2668,7 +2671,8 @@
             "SERIAL_FC",
             "TRNG",
             "FLASH",
-            "MPU"
+            "MPU",
+            "USBDEVICE"
         ],
         "detect_code": ["0796"],
         "release_versions": ["2", "5"],
@@ -2771,7 +2775,8 @@
             "SERIAL_ASYNCH",
             "SERIAL_FC",
             "FLASH",
-            "MPU"
+            "MPU",
+            "USBDEVICE"
         ],
         "release_versions": ["2", "5"],
         "device_name": "STM32F446ZE"
@@ -3641,7 +3646,8 @@
             "TRNG",
             "FLASH",
             "QSPI",
-            "MPU"
+            "MPU",
+            "USBDEVICE"
         ],
         "release_versions": ["2", "5"],
         "device_name": "STM32F469NI",