global: Migrate CONFIG_DW_WDT_CLOCK_KHZ to CFG

Perform a simple rename of CONFIG_DW_WDT_CLOCK_KHZ to CFG_DW_WDT_CLOCK_KHZ

Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/drivers/watchdog/designware_wdt.c b/drivers/watchdog/designware_wdt.c
index f8df191..447a22d 100644
--- a/drivers/watchdog/designware_wdt.c
+++ b/drivers/watchdog/designware_wdt.c
@@ -132,7 +132,7 @@
 		goto err;
 	}
 #else
-	priv->clk_khz = CONFIG_DW_WDT_CLOCK_KHZ;
+	priv->clk_khz = CFG_DW_WDT_CLOCK_KHZ;
 #endif
 
 	if (CONFIG_IS_ENABLED(DM_RESET) &&