r600g: evergreen fix for new design

Signed-off-by: Jerome Glisse <jglisse@redhat.com>
diff --git a/src/gallium/winsys/r600/drm/r600_priv.h b/src/gallium/winsys/r600/drm/r600_priv.h
index 6023f21..92b2eb1 100644
--- a/src/gallium/winsys/r600/drm/r600_priv.h
+++ b/src/gallium/winsys/r600/drm/r600_priv.h
@@ -39,6 +39,7 @@
 	unsigned			device;
 	unsigned			family;
 	enum chip_class			chip_class;
+	boolean				use_mem_constant; /* true for evergreen */
 };
 
 struct radeon *r600_new(int fd, unsigned device);