ACPI S3: Replace acpi_is_wakeup()

It was supposed to return true for both S2 and S3, but
level S2 was never stored in acpi_slp_type or otherwise
implemented.

Change-Id: Ida0165e647545069c0d42d38b9f45a95e78dacbe
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/47693
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/acpi/acpi.c

@@ -1541,7 +1541,7 @@ void *acpi_find_wakeup_vector(void)
 	void *wake_vec;
 	int i;
 
-	if (!acpi_is_wakeup())
+	if (!acpi_is_wakeup_s3())
 		return NULL;
 
 	printk(BIOS_DEBUG, "Trying to find the wakeup vector...\n");