Rename SPL_WATCHDOG_SUPPORT to SPL_WATCHDOG

Rename this option so that CONFIG_IS_ENABLED can be used with it.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/gwventana_emmc_defconfig b/configs/gwventana_emmc_defconfig
index 8740f27..4c40e99 100644
--- a/configs/gwventana_emmc_defconfig
+++ b/configs/gwventana_emmc_defconfig
@@ -41,7 +41,7 @@
 CONFIG_SPL_I2C_SUPPORT=y
 CONFIG_SPL_OS_BOOT=y
 CONFIG_SPL_POWER=y
-CONFIG_SPL_WATCHDOG_SUPPORT=y
+CONFIG_SPL_WATCHDOG=y
 CONFIG_HUSH_PARSER=y
 CONFIG_SYS_PROMPT="Ventana > "
 CONFIG_CMD_BOOTZ=y