microblaze: Enable watchdog via defconfig

DM watchdog should be enabled by default.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
diff --git a/configs/microblaze-generic_defconfig b/configs/microblaze-generic_defconfig
index 6ba7022..c366a80 100644
--- a/configs/microblaze-generic_defconfig
+++ b/configs/microblaze-generic_defconfig
@@ -56,3 +56,5 @@
 CONFIG_XILINX_EMACLITE=y
 CONFIG_SYS_NS16550=y
 CONFIG_XILINX_UARTLITE=y
+CONFIG_WDT=y
+CONFIG_XILINX_TB_WATCHDOG=y