Simplicy QSPIF target overrides for PSoC6

All current PSoC 6 targets support the same QSPI frequency and minimum
program size. So specify a single entry rather than duplicating for
each device.

Author: Kyle Kearney

components/storage/blockdevice/COMPONENT_QSPIF/mbed_lib.json

@@ -39,23 +39,7 @@
             "QSPI_MIN_READ_SIZE": "4",
             "QSPI_MIN_PROG_SIZE": "4"
         }, 
-        "CY8CKIT_062S2_43012": {
-            "QSPI_FREQ": "50000000",
-            "QSPI_MIN_PROG_SIZE": "512"
-        },
-        "CY8CPROTO_062_4343W": {
-            "QSPI_FREQ": "50000000",
-            "QSPI_MIN_PROG_SIZE": "512"
-        },
-        "CY8CKIT_062_WIFI_BT": {
-            "QSPI_FREQ": "50000000",
-            "QSPI_MIN_PROG_SIZE": "512"
-        },
-        "CY8CKIT_062_BLE": {
-            "QSPI_FREQ": "50000000",
-            "QSPI_MIN_PROG_SIZE": "512"
-        },
-        "CYW943012P6EVB_01": {
+        "MCU_PSOC6": {
             "QSPI_FREQ": "50000000",
             "QSPI_MIN_PROG_SIZE": "512"
         }