ACPI: video: fix build for CONFIG_ACPI=n

In file included from drivers/gpu/drm/i915/intel_opregion.c:30:
include/acpi/video.h:22: warning: ‘struct acpi_device’ declared inside parameter list
...
include/acpi/video.h:24: error: ‘ENODEV’ undeclared (first use in this function)

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Len Brown <len.brown@intel.com>