x86: apl: Skip init code when chain loading

When U-Boot is not the first-stage bootloader the FSP-S init must be
skipped. Update it to add a check.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
diff --git a/arch/x86/cpu/apollolake/fsp_s.c b/arch/x86/cpu/apollolake/fsp_s.c
index 17cf168..7ef169b 100644
--- a/arch/x86/cpu/apollolake/fsp_s.c
+++ b/arch/x86/cpu/apollolake/fsp_s.c
@@ -566,6 +566,8 @@
 	struct udevice *dev, *itss;
 	int ret;
 
+	if (!ll_boot_init())
+		return 0;
 	/*
 	 * This must be called before any devices are probed. Put any probing
 	 * into arch_fsps_preinit() above.