add status register number config

Author: daniel-723

storage/blockdevice/COMPONENT_QSPIF/mbed_lib.json

@@ -18,11 +18,13 @@
         "QSPI_POLARITY_MODE": 0,
         "QSPI_FREQ": "40000000",
         "QSPI_MIN_READ_SIZE": "1",
-        "QSPI_MIN_PROG_SIZE": "1"
+        "QSPI_MIN_PROG_SIZE": "1",
+        "QSPI_NUM_STATUS_REGISTER":"2"
     },
     "target_overrides": {
         "MX25R6435F": {
-            "QSPI_FREQ": "8000000"
+            "QSPI_FREQ": "8000000",
+	    "QSPI_NUM_STATUS_REGISTER":"3"
         },
         "MX25L51245G": {
             "QSPI_FREQ": "8000000"

storage/blockdevice/COMPONENT_QSPIF/source/QSPIFBlockDevice.cpp

@@ -1093,7 +1093,7 @@ int QSPIFBlockDevice::_handle_vendor_quirks()
             // 3. Should never attempt to enable 4-byte addressing (it causes reads and writes to fail)
             tr_debug("Applying quirks for macronix");
             _needs_fast_mode = true;
-            _num_status_registers = 3;
+            _num_status_registers = MBED_CONF_QSPI_NUM_STATUS_REGISTER;
             _read_status_reg_2_inst = QSPIF_INST_RDCR;
             _attempt_4_byte_addressing = false;
             break;