board_f: init designware watchdog if CONFIG_DESIGNWARE_WATCHDOG=y

The designware watchdog init is skipped even if CONFIG_DESIGNWARE_WATCHDOG
is enabled. Fix it.

Signed-off-by: Anatolij Gustschin <agust@denx.de>
diff --git a/common/board_f.c b/common/board_f.c
index d405b5b..05f6026 100644
--- a/common/board_f.c
+++ b/common/board_f.c
@@ -117,6 +117,7 @@
 # if defined(CONFIG_HW_WATCHDOG) && (defined(CONFIG_BLACKFIN) || \
 	defined(CONFIG_M68K) || defined(CONFIG_MICROBLAZE) || \
 	defined(CONFIG_SH) || defined(CONFIG_AT91SAM9_WATCHDOG) || \
+	defined(CONFIG_DESIGNWARE_WATCHDOG) || \
 	defined(CONFIG_IMX_WATCHDOG))
 	hw_watchdog_init();
 # endif