get vgabios command to build in

This program was broken by f94aed87730. This points to a weakness
in our CI: changes in coreboot itself broke a utility and it
was not caught for a year.

This builds, but in most ways, it seems like it would never work.
Many important bits are unsupported, particularly devfn and
tracing.

It seems the best path forward is to revert the 2015 patch that
converted it to using YABEL. The vgabios code prior to that patch
builds without warning and still works.

But it's probably worth getting this code to build.

Change-Id: I48e13e31deee0100a616a2f1d08ca84b9c470219
Signed-off-by: Ronald G Minnich <rminnich@gmail.com>
---
M src/device/oprom/x86emu/x86emui.h
M src/device/oprom/yabel/device.h
M src/device/oprom/yabel/interrupt.c
M src/device/oprom/yabel/pmm.h
M util/testing/Makefile.inc
M util/vgabios/device.c
M util/vgabios/testbios.c
7 files changed, 18 insertions(+), 8 deletions(-)