Corrected INIT_FREQUENCY macro SD is appended by tools

Author: deepikabhavnani

components/storage/blockdevice/COMPONENT_SD/config/mbed_lib.json

@@ -8,7 +8,7 @@
         "FSFAT_SDCARD_INSTALLED": 1,
         "CMD_TIMEOUT": 10000,
         "CMD0_IDLE_STATE_RETRIES": 5,
-        "SD_INIT_FREQUENCY": 100000,
+        "INIT_FREQUENCY": 100000,
         "CRC_ENABLED": 1
     },
     "target_overrides": {