drm/i915/bdw: display stuff

Just enough to make the code not barf...

Init BDW display to look like HSW. For the simulator this should be
fine, but this will probably require more work.

Signed-off-by: Ben Widawsky <ben@bwidawsk.net>
[danvet: Add a FIXME comment about RCS flips being untested on bdw.
Also add a note that hblank events are reserved on bdw+ in DERRMR.]
Reviewed-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
diff --git a/drivers/gpu/drm/i915/i915_reg.h b/drivers/gpu/drm/i915/i915_reg.h
index f897a70..48c3aef 100644
--- a/drivers/gpu/drm/i915/i915_reg.h
+++ b/drivers/gpu/drm/i915/i915_reg.h
@@ -743,6 +743,7 @@
 #define   FPGA_DBG_RM_NOCLAIM	(1<<31)
 
 #define DERRMR		0x44050
+/* Note that HBLANK events are reserved on bdw+ */
 #define   DERRMR_PIPEA_SCANLINE		(1<<0)
 #define   DERRMR_PIPEA_PRI_FLIP_DONE	(1<<1)
 #define   DERRMR_PIPEA_SPR_FLIP_DONE	(1<<2)