QSPIF: Attempt 4-byte addressing on Macronix chips

mbed-os PR 11531 introduced 4-byte addressing in the QSPIF block device:

ARMmbed#11531

During testing it was found that this code broke on the NRF52840_DK and
DISCO_F769NI.

The NRF52840_DK controller seems unable to handle 4-byte addressing at
all and has been disabled entirely in another code section.

The DISCO_F769NI breakage was attributed to the flash chip but after more
research I believe this is related to the QSPI controller, not the 4-byte
addressing itself.

Now that the QSPI controller has a workaround, enable 4-byte addressing
again and hope it works fine this time.

storage/blockdevice/COMPONENT_QSPIF/source/QSPIFBlockDevice.cpp

@@ -1095,7 +1095,6 @@ int QSPIFBlockDevice::_handle_vendor_quirks()
             _needs_fast_mode = true;
             _num_status_registers = 3;
             _read_status_reg_2_inst = QSPIF_INST_RDCR;
-            _attempt_4_byte_addressing = false;
             break;
         case 0x9d:
             // ISSI devices have only one status register