drm/i915: allow tiled front buffers on 965+

This patch corrects a pretty big oversight in the KMS code for 965+
chips.  The current code is missing tiled surface register programming,
so userland can allocate a tiled surface and use it for mode setting,
resulting in corruption.  This patch fixes that, allowing for tiled
front buffers on 965+.

Cc: stable@kernel.org
Tested-by: Arkadiusz Miskiewicz <arekm@maven.pl>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>
Signed-off-by: Eric Anholt <eric@anholt.net>

drivers/gpu/drm/i915/i915_reg.h

@@ -1446,6 +1446,7 @@
 #define   DISPPLANE_NO_LINE_DOUBLE		0
 #define   DISPPLANE_STEREO_POLARITY_FIRST	0
 #define   DISPPLANE_STEREO_POLARITY_SECOND	(1<<18)
+#define   DISPPLANE_TILED			(1<<10)
 #define DSPAADDR		0x70184
 #define DSPASTRIDE		0x70188
 #define DSPAPOS			0x7018C /* reserved */