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/am335x_shc_ict_defconfig b/configs/am335x_shc_ict_defconfig
index 51de7af..4ec255f 100644
--- a/configs/am335x_shc_ict_defconfig
+++ b/configs/am335x_shc_ict_defconfig
@@ -32,7 +32,7 @@
 # CONFIG_SPL_NAND_SUPPORT is not set
 CONFIG_SPL_OS_BOOT=y
 CONFIG_SPL_POWER=y
-CONFIG_SPL_WATCHDOG_SUPPORT=y
+CONFIG_SPL_WATCHDOG=y
 CONFIG_SPL_YMODEM_SUPPORT=y
 # CONFIG_SPL_AM33XX_ENABLE_RTC32K_OSC is not set
 CONFIG_SYS_PROMPT="U-Boot# "