arm: socfpga: socfpga_stratix10: enable wdt command by default

In latest u-boot code, watchdog feature is implemented, so enable
wdt command by default.

Signed-off-by: Meng Li <Meng.Li@windriver.com>
diff --git a/configs/socfpga_stratix10_defconfig b/configs/socfpga_stratix10_defconfig
index bbbae14..f83a90c 100644
--- a/configs/socfpga_stratix10_defconfig
+++ b/configs/socfpga_stratix10_defconfig
@@ -39,6 +39,7 @@
 CONFIG_CMD_EXT4=y
 CONFIG_CMD_FAT=y
 CONFIG_CMD_FS_GENERIC=y
+CONFIG_CMD_WDT=y
 CONFIG_ENV_IS_IN_MMC=y
 CONFIG_SYS_RELOC_GD_ENV_ADDR=y
 CONFIG_NET_RANDOM_ETHADDR=y