tty: serial: fsl_lpuart: remove the dev.coherent_dma_mask zero setting

By default, .of_dma_configure() init dev.coherent_dma_mask to BIT(32) that
match the eDMA address range. If re-init dev.coherent_dma_mask to zero, then
streaming dma mapping will go swiotlb dma_map, if swiotlb is not initalized
then it causes mapping failed.
Signed-off-by: Fugang Duan <fugang.duan@nxp.com>
Link: https://lore.kernel.org/r/20190717051930.15514-2-fugang.duan@nxp.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/fsl_lpuart.c

@@ -2320,8 +2320,6 @@ static int lpuart_probe(struct platform_device *pdev)
 	if (!sport)
 		return -ENOMEM;
 
-	pdev->dev.coherent_dma_mask = 0;
-
 	ret = of_alias_get_id(np, "serial");
 	if (ret < 0) {
 		ret = ida_simple_get(&fsl_lpuart_ida, 0, UART_NR, GFP_KERNEL);