Remove json setting for NUCLEO_F207ZG that was not part of this commit

Author: linlingao

components/storage/blockdevice/COMPONENT_SD/mbed_lib.json

@@ -166,12 +166,6 @@
             "SPI_CLK": "D13",
             "SPI_CS": "D9"
         },
-        "NUCLEO_F207ZG": {
-             "SPI_MOSI": "PC_12",
-             "SPI_MISO": "PC_11",
-             "SPI_CLK":  "PC_10",
-             "SPI_CS":   "PA_15"
-        },
         "CC3220SF_LAUNCHXL": {
             "SPI_MOSI": "D11",
             "SPI_MISO": "D12",