x86: acpi: Turn on ACPI mode for S3

Before jumping to OS waking up vector, we need turn on ACPI mode
for S3, just like what we do for a normal boot.

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

arch/x86/lib/acpi_s3.c

@@ -24,6 +24,9 @@ void acpi_resume(struct acpi_fadt *fadt)
 {
 	void *wake_vec;
 
+	/* Turn on ACPI mode for S3 */
+	enter_acpi_mode(fadt->pm1a_cnt_blk);
+
 	wake_vec = acpi_find_wakeup_vector(fadt);
 
 	post_code(POST_OS_RESUME);