arm64: zynqmp: Enable WDT command

Enable watchdog command to be able to work with watchdogs.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>

configs/xilinx_zynqmp_virt_defconfig

@@ -54,6 +54,7 @@ CONFIG_CMD_SF_TEST=y
 CONFIG_CMD_SPI=y
 CONFIG_CMD_USB=y
 CONFIG_CMD_USB_MASS_STORAGE=y
+CONFIG_CMD_WDT=y
 CONFIG_CMD_TFTPPUT=y
 CONFIG_CMD_BMP=y
 CONFIG_CMD_CACHE=y