pxm2: switch to DM_I2C

Enable DM_I2C to avoid board removal warning.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
Cc: Enrico Leto <enrico.leto@siemens.com>
diff --git a/configs/pxm2_defconfig b/configs/pxm2_defconfig
index 366d8fc..c2f8693 100644
--- a/configs/pxm2_defconfig
+++ b/configs/pxm2_defconfig
@@ -89,7 +89,8 @@
 CONFIG_BOOTCOUNT_ENV=y
 CONFIG_DFU_NAND=y
 CONFIG_SYS_DFU_DATA_BUF_SIZE=0x100000
-CONFIG_SYS_I2C_LEGACY=y
+CONFIG_DM_I2C=y
+# CONFIG_SPL_DM_I2C is not set
 CONFIG_SPL_SYS_I2C_LEGACY=y
 CONFIG_SYS_I2C_SPEED=400000
 # CONFIG_SPL_DM_MMC is not set