dm: arm: ls1021a: add i2c DM support

This supports i2c DM and enables CONFIG_DM_I2C
for SoC LS1021A

Signed-off-by: Biwen Li <biwen.li@nxp.com>
Signed-off-by: Priyanka Jain <priyanka.jain@nxp.com>
diff --git a/include/configs/ls1021atsn.h b/include/configs/ls1021atsn.h
index bdb4273..984df62 100644
--- a/include/configs/ls1021atsn.h
+++ b/include/configs/ls1021atsn.h
@@ -1,5 +1,5 @@
 /* SPDX-License-Identifier: GPL-2.0
- * Copyright 2016-2018 NXP Semiconductors
+ * Copyright 2016-2019 NXP Semiconductors
  * Copyright 2019 Vladimir Oltean <olteanv@gmail.com>
  */
 
@@ -107,7 +107,12 @@
 #define CONFIG_BAUDRATE			115200
 
 /* I2C */
+#ifndef CONFIG_DM_I2C
 #define CONFIG_SYS_I2C
+#else
+#define CONFIG_I2C_SET_DEFAULT_BUS_NUM
+#define CONFIG_I2C_DEFAULT_BUS_NUMBER 0
+#endif
 #define CONFIG_SYS_I2C_MXC
 #define CONFIG_SYS_I2C_MXC_I2C1		/* enable I2C bus 1 */
 #define CONFIG_SYS_I2C_MXC_I2C2		/* enable I2C bus 2 */