x86: fsp: acpi: Pass different boot mode to FSP init

When ACPI S3 resume is turned on, we should pass different boot mode
to FSP init instead of default BOOT_FULL_CONFIG.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>