mb/google/dedede/var/kracko: Add FW_CONFIG probe for EXT_VR

Add FW_CONFIG probe for absent ANPEC APW8738BQBI IC on kracko.

BUG=b:223687184
TEST=emerge-dedede coreboot

Signed-off-by: Robert Chen <robert.chen@quanta.corp-partner.google.com>
Change-Id: Ib12265591e679e6b9ed34299f1256db05147eaef
Reviewed-on: https://review.coreboot.org/c/coreboot/+/63111
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Henry Sun <henrysun@google.com>
Reviewed-by: Shou-Chieh Hsu <shouchieh@google.com>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Reviewed-by: Eric Lai <eric_lai@quanta.corp-partner.google.com>

src/mainboard/google/dedede/variants/kracko/Makefile.inc

@@ -4,4 +4,6 @@ ramstage-y += variant.c
 
 ramstage-y += gpio.c
 
+ramstage-y += ramstage.c
+
 smm-y += variant.c

src/mainboard/google/dedede/variants/kracko/ramstage.c

@@ -0,0 +1,17 @@
+/* SPDX-License-Identifier: GPL-2.0-or-later */
+
+#include <baseboard/variants.h>
+#include <fw_config.h>
+#include <soc/soc_chip.h>
+
+static void ext_vr_update(void)
+{
+	struct soc_intel_jasperlake_config *cfg = config_of_soc();
+	if (fw_config_probe(FW_CONFIG(EXT_VR, EXT_VR_ABSENT)))
+		cfg->disable_external_bypass_vr = 1;
+}
+
+void variant_devtree_update(void)
+{
+	ext_vr_update();
+}