drm/radeon: add rv740 drm support.

This adds drm support for the RV740 family of chips to the r600 support code.

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 8071d96..e266e5f 100644
--- a/drivers/gpu/drm/radeon/radeon_drv.h
+++ b/drivers/gpu/drm/radeon/radeon_drv.h
@@ -146,6 +146,7 @@
 	CHIP_RV770,
 	CHIP_RV730,
 	CHIP_RV710,
+	CHIP_RV740,
 	CHIP_LAST,
 };