soc/intel/tigerlake: Add mainboard hook for overriding SoC config

TEST=util/abuild/abuild -t GOOGLE_VOLTEER -c max -x
BUG=b:154333137

Change-Id: Iff28e4a29fab5c22c410cdc743d0402134c4ac56
Signed-off-by: jbk@chromium.org
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44914
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/soc/intel/tigerlake/fsp_params.c

@@ -82,6 +82,11 @@ static const pci_devfn_t serial_io_dev[] = {
 	PCH_DEVFN_UART2
 };
 
+__weak void mainboard_update_soc_chip_config(struct soc_intel_tigerlake_config *config)
+{
+	/* Override settings per board. */
+}
+
 /* UPD parameters to be initialized before SiliconInit */
 void platform_fsp_silicon_init_params_cb(FSPS_UPD *supd)
 {
@@ -92,6 +97,7 @@ void platform_fsp_silicon_init_params_cb(FSPS_UPD *supd)
 	struct device *dev;
 	struct soc_intel_tigerlake_config *config;
 	config = config_of_soc();
+	mainboard_update_soc_chip_config(config);
 
 	/* Parse device tree and enable/disable Serial I/O devices */
 	parse_devicetree(params);

src/soc/intel/tigerlake/include/soc/ramstage.h

@@ -9,6 +9,7 @@
 #include <soc/soc_chip.h>
 
 void mainboard_silicon_init_params(FSP_S_CONFIG *params);
+void mainboard_update_soc_chip_config(struct soc_intel_tigerlake_config *config);
 void soc_init_pre_device(void *chip_info);
 
 #endif