Add support for etc/hardware-info fw_cfg file

Add support for etc/hardware-info fw_cfg file

edk2 looks for the etc/hardware-info fw_cfg file to discover hardware
which can not easily be found in other ways.  Entries consist of a
header with hardware type and entry size (HARDWARE_INFO_HEADER),
followed by the actual hardware description (which is type specific).
The file can have multiple entries.

This patch adds the infrastructure to add entries to the file and an
entry struct for simple devices (HARDWARE_INFO_SIMPLE_DEVICE) which have
an mmio address only.

Signed-off-by: Gerd Hoffmann <kraxel@redhat.com>
Message-ID: <20250225163031.1409078-2-kraxel@redhat.com>