drm/radeon/kms: disable HDMI audio for now on rv710/rv730

Support isn't correct yet and we are getting green tinges on the
displays.

Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/r600_audio.c

@@ -35,7 +35,7 @@
  */
 static int r600_audio_chipset_supported(struct radeon_device *rdev)
 {
-	return rdev->family >= CHIP_R600
+	return (rdev->family >= CHIP_R600 && rdev->family < CHIP_RV710)
 		|| rdev->family == CHIP_RS600
 		|| rdev->family == CHIP_RS690
 		|| rdev->family == CHIP_RS740;