drivers/vpd: Add VPD region to default FMAP when selected

drivers/vpd: Add VPD region to default FMAP when selected

Currently, use of the VPD driver to read VPD tables from flash
requires the use of a custom FMAP with one or more VPD regions.
Extend this funtionality to boards using the default FMAP by
creating a dedicated VPD region when the driver is selected.

Test: build qemu target with CONFIG_VPD selected, verify entry
added to build/fmap.fmd.

Change-Id: Ie9e3c7cf11a6337a43223a6037632a4d9c84d988
Signed-off-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49049
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>