configs: imx8mm-cl-iot-gate: enable extension command

For imx8mm-cl-iot-gate we can use extension command to scan
extension boards attached on the mainboard. We enable the
extension command by default for users to detect the extension
boards.

Signed-off-by: Ying-Chun Liu (PaulLiu) <paulliu@debian.org>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Fabio Estevam <festevam@gmail.com>
Cc: NXP i.MX U-Boot Team <uboot-imx@nxp.com>
diff --git a/configs/imx8mm-cl-iot-gate_defconfig b/configs/imx8mm-cl-iot-gate_defconfig
index 0708498..b294548 100644
--- a/configs/imx8mm-cl-iot-gate_defconfig
+++ b/configs/imx8mm-cl-iot-gate_defconfig
@@ -47,6 +47,7 @@
 CONFIG_SYS_PBSIZE=2074
 CONFIG_SYS_BOOTM_LEN=0x2000000
 CONFIG_CMD_BOOTEFI_SELFTEST=y
+CONFIG_CMD_EXTENSION=y
 CONFIG_CMD_NVEDIT_EFI=y
 CONFIG_CMD_EEPROM=y
 CONFIG_CMD_SHA1SUM=y
@@ -96,6 +97,7 @@
 CONFIG_FASTBOOT_FLASH=y
 CONFIG_FASTBOOT_FLASH_MMC_DEV=2
 CONFIG_MXC_GPIO=y
+CONFIG_DM_PCA953X=y
 CONFIG_DM_I2C=y
 CONFIG_DM_KEYBOARD=y
 CONFIG_MISC=y