configs: ls1043ardb: enable DM_SERIAL

As the serial devices are configured in the device tree, enable
DM_SERIAL in the ls1043ardb defconfigs.

Signed-off-by: Camelia Groza <camelia.groza@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
diff --git a/configs/ls1043ardb_defconfig b/configs/ls1043ardb_defconfig
index e796c0a..ae8600f 100644
--- a/configs/ls1043ardb_defconfig
+++ b/configs/ls1043ardb_defconfig
@@ -89,7 +89,9 @@
 CONFIG_PCIE_LAYERSCAPE_RC=y
 CONFIG_SYS_QE_FW_ADDR=0x60940000
 CONFIG_SYS_QE_FMAN_FW_IN_NOR=y
-CONFIG_SYS_NS16550_SERIAL=y
+CONFIG_SPECIFY_CONSOLE_INDEX=y
+CONFIG_DM_SERIAL=y
+CONFIG_SYS_NS16550=y
 CONFIG_SPI=y
 CONFIG_DM_SPI=y
 CONFIG_USB=y