spi: fsl-lpspi: use true,false for bool variable

Fixes coccicheck warning:

drivers/spi/spi-fsl-lpspi.c:472:2-19: WARNING: Assignment of 0/1 to bool variable
drivers/spi/spi-fsl-lpspi.c:474:2-19: WARNING: Assignment of 0/1 to bool variable

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: zhengbin <zhengbin13@huawei.com>
Link: https://lore.kernel.org/r/1577159526-33689-2-git-send-email-zhengbin13@huawei.com
Signed-off-by: Mark Brown <broonie@kernel.org>

drivers/spi/spi-fsl-lpspi.c

@@ -469,9 +469,9 @@ static int fsl_lpspi_setup_transfer(struct spi_controller *controller,
 		fsl_lpspi->watermark = fsl_lpspi->txfifosize;
 
 	if (fsl_lpspi_can_dma(controller, spi, t))
-		fsl_lpspi->usedma = 1;
+		fsl_lpspi->usedma = true;
 	else
-		fsl_lpspi->usedma = 0;
+		fsl_lpspi->usedma = false;
 
 	return fsl_lpspi_config(fsl_lpspi);
 }