Remove NUCLEO_F412ZG from example linking_list

Author: bcostm

tools/build_travis.py

@@ -186,13 +186,6 @@
                "usb"  : ["USB_1", "USB_2" ,"USB_3"],
              }
     },
-    {"target": "NUCLEO_F412ZG",
-     "toolchains": "GCC_ARM",
-     "tests": {""     : ["MBED_2", "MBED_10", "MBED_11", "MBED_16"],
-               "rtos" : ["RTOS_1", "RTOS_2", "RTOS_3"],
-               "usb"  : ["USB_1", "USB_2" ,"USB_3"],
-             }
-    },
     {"target": "NUCLEO_F429ZI",
      "toolchains": "GCC_ARM",
      "tests": {""     : ["MBED_2", "MBED_10", "MBED_11", "MBED_16"],