imx: ventana: enable DM_SERIAL

mxc_serial supports DM so lets use it.

Signed-off-by: Tim Harvey <tharvey@gateworks.com>
diff --git a/include/configs/gw_ventana.h b/include/configs/gw_ventana.h
index c8645ca..cefd16f 100644
--- a/include/configs/gw_ventana.h
+++ b/include/configs/gw_ventana.h
@@ -49,6 +49,7 @@
 #ifndef CONFIG_SPL_BUILD
 #define CONFIG_DM
 #define CONFIG_DM_GPIO
+#define CONFIG_DM_SERIAL
 #define CONFIG_CMD_DM
 #endif