board/guybrush: Enable EC_VBOOT_SUPPORT

Enabling EC_VBOOT_SUPPORT requires the ability to check if EC is
secure/trusted. But the guybrush board versions with H1 DB does not have
the required hardware support. Hence add a virtual GPIO to emulate the
EC_IN_RW only for those board versions and enable EC_VBOOT_SUPPORT.

BUG=b:185277224
BRANCH=None
TEST=Build and boot to OS in guybrush both in normal mode and recovery
mode. Ensure that the EC software sync also works fine with early EC
sync disabled in coreboot.

Change-Id: I8c6647ff455df98ede6164ced306a648c9d26dfe
Signed-off-by: Karthikeyan Ramasubramanian <kramasub@google.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/depthcharge/+/2832032
Tested-by: Karthikeyan Ramasubramanian <kramasub@chromium.org>
Reviewed-by: Mathew King <mathewk@chromium.org>
Commit-Queue: Karthikeyan Ramasubramanian <kramasub@chromium.org>