Added this code in SparkFun_u-blox_GNSS_Arduino_Libary.cpp in the function pushRawData.

_spiPort->beginTransaction(SPISettings(_spiSpeed, MSBFIRST, SPI_MODE0));
digitalWrite(_csPin, LOW);
for (uint16_t i = 0; i < numDataBytes; i++) {
    spiTransfer(dataBytes[i]);
}
digitalWrite(_csPin, HIGH);
_spiPort->endTransaction();