altera_uart: change ioremap to map_physmem

Change ioremap() to map_physmem(), as it is more used in u-boot.

Signed-off-by: Thomas Chou <thomas@wytron.com.tw>
Reviewed-by: Marek Vasut <marex@denx.de>

drivers/serial/altera_uart.c

@@ -89,8 +89,9 @@ static int altera_uart_ofdata_to_platdata(struct udevice *dev)
 {
 	struct altera_uart_platdata *plat = dev_get_platdata(dev);
 
-	plat->regs = ioremap(dev_get_addr(dev),
-		sizeof(struct altera_uart_regs));
+	plat->regs = map_physmem(dev_get_addr(dev),
+				 sizeof(struct altera_uart_regs),
+				 MAP_NOCACHE);
 	plat->uartclk = fdtdec_get_int(gd->fdt_blob, dev->of_offset,
 		"clock-frequency", 0);