drm/radeon/kms: fix handling of tex lookup disable in cs checker on r2xx

There are cases when multiple texture units have to be enabled,
but not actually used to sample.  This patch checks to see if
the lookup_disable bit is set and if so, skips the texture check.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=25544

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/r100_track.h b/drivers/gpu/drm/radeon/r100_track.h
index f47cdca..af65600 100644
--- a/drivers/gpu/drm/radeon/r100_track.h
+++ b/drivers/gpu/drm/radeon/r100_track.h
@@ -46,6 +46,7 @@
 	unsigned		height_11;
 	bool			use_pitch;
 	bool			enabled;
+	bool                    lookup_disable;
 	bool			roundup_w;
 	bool			roundup_h;
 	unsigned                compress_format;