drm/i915: Simplify processing of the golden render context state

Rewrite i915_gem_render_state.c for the purposes of clarity and
compactness, in the process we can eliminate some dodgy math that did
not handle 64bit addresses correctly.

Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>
Cc: Ville Syrjälä <ville.syrjala@linux.intel.com>
Cc: Damien Lespiau <damien.lespiau@intel.com>
Cc: Mika Kuoppala <mika.kuoppala@intel.com>
Reviewed-by: Mika Kuoppala <mika.kuoppala@intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/intel_renderstate_gen6.c b/drivers/gpu/drm/i915/intel_renderstate_gen6.c
index 740538a..56c1429 100644
--- a/drivers/gpu/drm/i915/intel_renderstate_gen6.c
+++ b/drivers/gpu/drm/i915/intel_renderstate_gen6.c
@@ -6,6 +6,7 @@
 	0x0000002c,
 	0x000001e0,
 	0x000001e4,
+	-1,
 };
 
 static const u32 gen6_null_state_batch[] = {