drm/radeon: Add support for RS880 chips

These are new AMD IGP 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_drv.h b/drivers/gpu/drm/radeon/radeon_drv.h
index 127d045..3933f82 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.h
+++ b/drivers/gpu/drm/radeon/radeon_drv.h
@@ -143,6 +143,7 @@
 	CHIP_RV635,
 	CHIP_RV670,
 	CHIP_RS780,
+	CHIP_RS880,
 	CHIP_RV770,
 	CHIP_RV730,
 	CHIP_RV710,