drm/panel: simple: Check against num_timings when setting preferred for timing

commit 230c5b44 upstream.

In the loop on .timings, we should check .num_timings to see if it's the
only mode specified, not .num_modes, which should be used with .modes.

Fixes: cda55372 ("drm/panel: simple: Set appropriate mode type")
Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/gpu/drm/panel/panel-simple.c

@@ -120,7 +120,7 @@ static int panel_simple_get_fixed_modes(struct panel_simple *panel)
 
 		mode->type |= DRM_MODE_TYPE_DRIVER;
 
-		if (panel->desc->num_modes == 1)
+		if (panel->desc->num_timings == 1)
 			mode->type |= DRM_MODE_TYPE_PREFERRED;
 
 		drm_mode_probed_add(connector, mode);