hw/arm/virt-acpi-build.c: Add missing header

hw/arm/virt-acpi-build.c: Add missing header

virt-acpi-build.c uses warn_report. However, it doesn't include
qemu/error-report.h directly, it include qemu/error-report.h via trace.h
if we enable log trace backend. But if we disable the log trace backend
(e.g., --enable-trace-backends=nop), then virt-acpi-build.c will not
include qemu/error-report.h any more and it will lead to build errors.
Include qemu/error-report.h directly in virt-acpi-build.c to avoid the
errors.

Fixes: 451b157041 ("acpi: Align the size to 128k")
Signed-off-by: Peng Liang <tcx4c70@gmail.com>
Reviewed-by: Ani Sinha <anisinha@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>
(mjt: move the #include higher as suggested by Ani Sinha)