drm/nv50: disregard dac outputs in nv50_sor_dpms()

Fixes DVI+VGA on my 9400, and likely a lot of other configurations that
got broken by the previos DVI-over-DP fix.
Signed-off-by: Ben Skeggs <bskeggs@redhat.com>

drivers/gpu/drm/nouveau/nv50_sor.c

@@ -101,6 +101,7 @@ nv50_sor_dpms(struct drm_encoder *encoder, int mode)
 		struct nouveau_encoder *nvenc = nouveau_encoder(enc);
 
 		if (nvenc == nv_encoder ||
+		    nvenc->disconnect != nv50_sor_disconnect ||
 		    nvenc->dcb->or != nv_encoder->dcb->or)
 			continue;