rockchip: ns16550: dm: convert fdt_get to dev_read

With the new dev_read functions available, we can convert the rockchip
architecture-specific drivers and common drivers used by these devices
over to the dev_read family of calls.

This covers the serial driver (ns16550 and compatible) used for the
Rockchip devices.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/serial/ns16550.c

@@ -434,10 +434,8 @@ int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
 	plat->base = (unsigned long)map_physmem(addr, 0, MAP_NOCACHE);
 #endif
 
-	plat->reg_offset = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
-				     "reg-offset", 0);
-	plat->reg_shift = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
-					 "reg-shift", 0);
+	plat->reg_offset = dev_read_u32_default(dev, "reg-offset", 0);
+	plat->reg_shift = dev_read_u32_default(dev, "reg-shift", 0);
 
 	err = clk_get_by_index(dev, 0, &clk);
 	if (!err) {
@@ -450,9 +448,8 @@ int ns16550_serial_ofdata_to_platdata(struct udevice *dev)
 	}
 
 	if (!plat->clock)
-		plat->clock = fdtdec_get_int(gd->fdt_blob, dev_of_offset(dev),
-					     "clock-frequency",
-					     CONFIG_SYS_NS16550_CLK);
+		plat->clock = dev_read_u32_default(dev, "clock-frequency",
+						   CONFIG_SYS_NS16550_CLK);
 	if (!plat->clock) {
 		debug("ns16550 clock not defined\n");
 		return -EINVAL;