drm/radeon: add GET_PARAM/INFO support for Z pipes

Needed for occlusion queries on rv530 chips.

Signed-off-by: Alex Deucher <alexdeucher@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
diff --git a/drivers/gpu/drm/radeon/radeon.h b/drivers/gpu/drm/radeon/radeon.h
index 79ad982..b519fb2 100644
--- a/drivers/gpu/drm/radeon/radeon.h
+++ b/drivers/gpu/drm/radeon/radeon.h
@@ -655,6 +655,7 @@
 	int				usec_timeout;
 	enum radeon_pll_errata		pll_errata;
 	int				num_gb_pipes;
+	int				num_z_pipes;
 	int				disp_priority;
 	/* BIOS */
 	uint8_t				*bios;