imx: mx6ulz: select DM_SERIAL

Select DM_SERIAL

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/configs/mx6ulz_14x14_evk_defconfig b/configs/mx6ulz_14x14_evk_defconfig
index 0c1b442..2df2ccd 100644
--- a/configs/mx6ulz_14x14_evk_defconfig
+++ b/configs/mx6ulz_14x14_evk_defconfig
@@ -48,6 +48,7 @@
 CONFIG_PINCTRL=y
 CONFIG_PINCTRL_IMX6=y
 CONFIG_DM_REGULATOR=y
+CONFIG_DM_SERIAL=y
 CONFIG_MXC_UART=y
 CONFIG_SPI=y
 CONFIG_DM_SPI=y