ls102xa: ddr4: Use LPUART as console output to verify DCU driver

On QDS board with DDR4 DIMM, LPUART is used as console
output to verify DCU driver. This patch adds
ls1021aqds_ddr4_nor_lpuart_defconfig for this support.

Signed-off-by: Alison Wang <alison.wang@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/configs/ls1021aqds_ddr4_nor_lpuart_defconfig b/configs/ls1021aqds_ddr4_nor_lpuart_defconfig
new file mode 100644
index 0000000..4d2714b
--- /dev/null
+++ b/configs/ls1021aqds_ddr4_nor_lpuart_defconfig
@@ -0,0 +1,3 @@
+CONFIG_SYS_EXTRA_OPTIONS="SYS_FSL_DDR4,LPUART"
+CONFIG_ARM=y
+CONFIG_TARGET_LS1021AQDS=y