arm: ls102xa: Add LPUART support for LS1021ATWR board

This patch adds LPUART support for LS1021ATWR board.
For ls1021atwr_nor_lpuart_defconfig, LPUART is used as the console.

Signed-off-by: Alison Wang <alison.wang@freescale.com>
Reviewed-by: York Sun <yorksun@freescale.com>
diff --git a/board/freescale/ls1021atwr/MAINTAINERS b/board/freescale/ls1021atwr/MAINTAINERS
index 9176706..e9f6f0a 100644
--- a/board/freescale/ls1021atwr/MAINTAINERS
+++ b/board/freescale/ls1021atwr/MAINTAINERS
@@ -5,5 +5,6 @@
 F:	include/configs/ls1021atwr.h
 F:	configs/ls1021atwr_nor_defconfig
 F:	configs/ls1021atwr_nor_SECURE_BOOT_defconfig
+F:	configs/ls1021atwr_nor_lpuart_defconfig
 F:	configs/ls1021atwr_sdcard_defconfig
 F:	configs/ls1021atwr_qspi_defconfig