Kconfig: Rename API to LEGACY_API

Update Kconfig use use CONFIG_LEGACY_API since the API is now
deprecated.

Signed-off-by: Simon Glass <sjg@chromium.org>

common/board_r.c

@@ -686,8 +686,8 @@ static void initcall_run_r(void)
 #endif
 	INITCALL(stdio_add_devices);
 	INITCALL(jumptable_init);
-#if CONFIG_IS_ENABLED(API)
-	INITCALL(api_init);
+#if CONFIG_IS_ENABLED(LEGACY_API)
+	INITCALL(legacy_api_init);
 #endif
 	INITCALL(console_init_r);	/* fully init console as a device */
 #if CONFIG_IS_ENABLED(DISPLAY_BOARDINFO_LATE)