msc_sm2s_imx8mp: Convert to DM_SERIAL

The conversion to DM_SERIAL is mandatory, so do the conversion.

Signed-off-by: Fabio Estevam <festevam@denx.de>
Reviewed-by: Ian Ray <ian.ray@gehealthcare.com>
diff --git a/configs/msc_sm2s_imx8mp_defconfig b/configs/msc_sm2s_imx8mp_defconfig
index bf1052d..9c27a72 100644
--- a/configs/msc_sm2s_imx8mp_defconfig
+++ b/configs/msc_sm2s_imx8mp_defconfig
@@ -97,6 +97,7 @@
 CONFIG_DM_REGULATOR=y
 CONFIG_DM_REGULATOR_FIXED=y
 CONFIG_DM_REGULATOR_GPIO=y
+CONFIG_DM_SERIAL=y
 CONFIG_MXC_UART=y
 CONFIG_SYSRESET=y
 CONFIG_SPL_SYSRESET=y