arm: ls102xa: Add LPUART support for LS1021AQDS board

This patch adds LPUART support for LS1021AQDS board.
For ls1021aqds_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/configs/ls1021aqds_nor_lpuart_defconfig b/configs/ls1021aqds_nor_lpuart_defconfig
new file mode 100644
index 0000000..29335ee
--- /dev/null
+++ b/configs/ls1021aqds_nor_lpuart_defconfig
@@ -0,0 +1,3 @@
+CONFIG_SYS_EXTRA_OPTIONS="LPUART"
++S:CONFIG_ARM=y
++S:CONFIG_TARGET_LS1021AQDS=y