mb/google/rex: Enable VPU device for Rex/Ovis baseboard

mb/google/rex: Enable VPU device for Rex/Ovis baseboard

This patch enables the Versatile Processing Unit (VPU) by default for
Rex/Ovis baseboard. VPU is a dedicated AI engine that is included in
the 14th generation "Meteor Lake" Core processors.

The VPU is designed to efficiently run AI models directly on the
system on chip (SoC). There is no power regression observed while
keeping the VPU default enabled to run AI models natively hence, this
patch enables the VPU by default.

BUG=b:332488817
TEST=Able to see VPU PCI device in lspci (0:11:0) list after booting
google/screebo to OS.

Change-Id: I8b3521c8ec613b002f971eaf9d346927fe8cd656
Signed-off-by: Subrata Banik <subratabanik@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/82422
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sumeet R Pawnikar <sumeet.r.pawnikar@intel.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Jamie Ryu <jamie.m.ryu@intel.com>
Reviewed-by: Dinesh Gehlot <digehlot@google.com>
Reviewed-by: Eric Lai <ericllai@google.com>