arm: ls1021atwr: Enable driver model lpuart serial driver

Convert ls1021atwr_nor_lpuart to driver model support. As a start,
enable lpuart serial port driver.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Alison Wang <alison.wang@nxp.com>
Tested-by: Alison Wang <alison.wang@nxp.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/arm/dts/Makefile b/arch/arm/dts/Makefile
index 5a6f75a..7706b41 100644
--- a/arch/arm/dts/Makefile
+++ b/arch/arm/dts/Makefile
@@ -93,7 +93,7 @@
 dtb-$(CONFIG_TARGET_STV0991) += stv0991.dtb
 
 dtb-$(CONFIG_LS102XA) += ls1021a-qds.dtb \
-	ls1021a-twr-duart.dtb
+	ls1021a-twr-duart.dtb ls1021a-twr-lpuart.dtb
 dtb-$(CONFIG_FSL_LSCH3) += fsl-ls2080a-qds.dtb \
 	fsl-ls2080a-rdb.dtb
 dtb-$(CONFIG_FSL_LSCH2) += fsl-ls1043a-qds.dtb \
diff --git a/arch/arm/dts/ls1021a-twr-lpuart.dts b/arch/arm/dts/ls1021a-twr-lpuart.dts
new file mode 100644
index 0000000..2941ec0
--- /dev/null
+++ b/arch/arm/dts/ls1021a-twr-lpuart.dts
@@ -0,0 +1,16 @@
+/*
+ * Freescale ls1021a TWR board device tree source
+ *
+ * Copyright 2013-2015 Freescale Semiconductor, Inc.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+/dts-v1/;
+#include "ls1021a-twr.dtsi"
+
+/ {
+	chosen {
+		stdout-path = &lpuart0;
+	};
+};
diff --git a/configs/ls1021atwr_nor_lpuart_defconfig b/configs/ls1021atwr_nor_lpuart_defconfig
index 58cd61f..599342f 100644
--- a/configs/ls1021atwr_nor_lpuart_defconfig
+++ b/configs/ls1021atwr_nor_lpuart_defconfig
@@ -1,7 +1,11 @@
 CONFIG_ARM=y
 CONFIG_TARGET_LS1021ATWR=y
+CONFIG_DM_SERIAL=y
+CONFIG_DEFAULT_DEVICE_TREE="ls1021a-twr-lpuart"
 CONFIG_SYS_EXTRA_OPTIONS="LPUART"
 # CONFIG_CMD_SETEXPR is not set
+CONFIG_OF_CONTROL=y
+CONFIG_DM=y
 CONFIG_NETDEVICES=y
 CONFIG_E1000=y
 CONFIG_FSL_LPUART=y