drm/i915/bdw: IS_GEN8 definition

No PCI ids yet, so nothing should happen.

Rebase-Note: This one needs replacement ;-)
Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
Reviewed-by: Damien Lespiau <damien.lespiau@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>

drivers/gpu/drm/i915/i915_drv.h

@@ -1749,6 +1749,7 @@ struct drm_i915_file_private {
 #define IS_GEN5(dev)	(INTEL_INFO(dev)->gen == 5)
 #define IS_GEN6(dev)	(INTEL_INFO(dev)->gen == 6)
 #define IS_GEN7(dev)	(INTEL_INFO(dev)->gen == 7)
+#define IS_GEN8(dev)	(INTEL_INFO(dev)->gen == 8)
 
 #define RENDER_RING		(1<<RCS)
 #define BSD_RING		(1<<VCS)