mb/google/brox/var/lotso: enable CNVi bluetooth

Lotso's WIFI_BT is same design as brox, copy from brox.

BUG=b:339612353
TEST=emerge-brox coreboot chromeos-bootimage and boot on

Change-Id: I3946297db7f10a31570f773bdc5665f9f472c9fe
Signed-off-by: Jian Tong <tongjian@huaqin.corp-partner.google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/83053
Reviewed-by: Wentao Qin <qinwentao@huaqin.corp-partner.google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Karthik Ramasubramanian <kramasub@google.com>
Reviewed-by: Subrata Banik <subratabanik@google.com>

src/mainboard/google/brox/variants/lotso/Makefile.mk

@@ -3,4 +3,5 @@
 bootblock-y += gpio.c
 romstage-y += memory.c
 romstage-y += gpio.c
+ramstage-$(CONFIG_FW_CONFIG) += variant.c
 ramstage-y += gpio.c

src/mainboard/google/brox/variants/lotso/variant.c

@@ -0,0 +1,20 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#include <assert.h>
+#include <baseboard/variants.h>
+#include <chip.h>
+#include <fw_config.h>
+#include <sar.h>
+
+void variant_update_soc_chip_config(struct soc_intel_alderlake_config *config)
+{
+	if (fw_config_probe(FW_CONFIG(WIFI_BT, WIFI_CNVI_WIFI6E))) {
+		printk(BIOS_INFO, "CNVi bluetooth enabled by fw_config\n");
+		config->cnvi_bt_core = true;
+	}
+}
+
+const char *get_wifi_sar_cbfs_filename(void)
+{
+	return get_wifi_sar_fw_config_filename(FW_CONFIG_FIELD(WIFI_BT));
+}