mb/google/dedede: Add GPIO stubs

Add stubbed out GPIO configuration and perform GPIO initialization
during bootblock and ramstage.

BUG=b:144768001
TEST=Build Test

Change-Id: I1397b6a433e5046650f64f7eb9a84c51eb0c7441
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38278
Reviewed-by: Aamir Bohra <aamir.bohra@intel.com>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/dedede/bootblock.c

@@ -6,9 +6,14 @@
  * SPDX-License-Identifier: GPL-2.0-or-later
  */
 
+#include <baseboard/variants.h>
 #include <bootblock_common.h>
 
 void bootblock_mainboard_init(void)
 {
-	/* TODO: Perform mainboard initialization */
+	const struct pad_config *pads;
+	size_t num;
+
+	pads = variant_early_gpio_table(&num);
+	gpio_configure_pads(pads, num);
 }