mb/google/dedede: Add ability to provide override GPIO table

For variants with slightly different GPIO configuration, add support to
pass an override GPIO configuration table.

BUG=None
TEST=Build and boot the waddledee mainboard.

Change-Id: I2f1c6dc2ea5499bff96a471c4461339ef01ee19a
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43279
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/mainboard/google/dedede/mainboard.c

@@ -22,11 +22,15 @@ static void mainboard_config_isst(void *unused)
 
 static void mainboard_init(void *chip_info)
 {
-	const struct pad_config *pads;
-	size_t num;
+	const struct pad_config *base_pads;
+	const struct pad_config *override_pads;
+	size_t base_num, override_num;
 
-	pads = variant_gpio_table(&num);
-	gpio_configure_pads(pads, num);
+	base_pads = variant_base_gpio_table(&base_num);
+	override_pads = variant_override_gpio_table(&override_num);
+
+	gpio_configure_pads_with_override(base_pads, base_num,
+		override_pads, override_num);
 }
 
 static void mainboard_dev_init(struct device *dev)

src/mainboard/google/dedede/variants/baseboard/gpio.c

@@ -420,12 +420,18 @@ static const struct pad_config early_gpio_table[] = {
 	PAD_CFG_GPI(GPP_S0, NONE, DEEP),
 };
 
-const struct pad_config *__weak variant_gpio_table(size_t *num)
+const struct pad_config *__weak variant_base_gpio_table(size_t *num)
 {
 	*num = ARRAY_SIZE(gpio_table);
 	return gpio_table;
 }
 
+const struct pad_config *__weak variant_override_gpio_table(size_t *num)
+{
+	*num = 0;
+	return NULL;
+}
+
 const struct pad_config *__weak variant_early_gpio_table(size_t *num)
 {
 	*num = ARRAY_SIZE(early_gpio_table);

src/mainboard/google/dedede/variants/baseboard/include/baseboard/variants.h

@@ -13,10 +13,11 @@
 /* The next set of functions return the gpio table and fill in the number of
  * entries for each table. */
 
-const struct pad_config *variant_gpio_table(size_t *num);
+const struct pad_config *variant_base_gpio_table(size_t *num);
 const struct pad_config *variant_early_gpio_table(size_t *num);
 const struct pad_config *variant_sleep_gpio_table(size_t *num);
 const struct cros_gpio *variant_cros_gpios(size_t *num);
+const struct pad_config *variant_override_gpio_table(size_t *num);
 
 /**
  * Get board's Hardware features as defined in FW_CONFIG