[PATCH] drm/drm_panel: fix EXPORT of drm_panel_of_backlight

[Sam Ravnborg]

Fix link failure for module builds of panels.
The conditional compilation around drm_panel_of_backlight()
was wrong for a module build.
Fix it using IS_ENABLED().

Fixes: 152dbdeab1b2 ("drm/panel: add backlight support")
Cc: Sam Ravnborg <sam at ravnborg.org>
Cc: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
Cc: Thierry Reding <thierry.reding at gmail.com>
Cc: Maarten Lankhorst <maarten.lankhorst at linux.intel.com>
Cc: Maxime Ripard <maxime.ripard at bootlin.com>
Cc: Sean Paul <sean at poorly.run>
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
Cc: Maxime Ripard <mripard at kernel.org>
Cc: dri-devel at lists.freedesktop.org
Signed-off-by: Sam Ravnborg <sam at ravnborg.org>
---
 drivers/gpu/drm/drm_panel.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/drm_panel.c b/drivers/gpu/drm/drm_panel.c
index 03395ad4d907..79ff3fdf6f6e 100644
--- a/drivers/gpu/drm/drm_panel.c
+++ b/drivers/gpu/drm/drm_panel.c
@@ -302,7 +302,7 @@ struct drm_panel *of_drm_find_panel(const struct device_node *np)
 EXPORT_SYMBOL(of_drm_find_panel);
 #endif
 
-#ifdef CONFIG_BACKLIGHT_CLASS_DEVICE
+#if IS_ENABLED(CONFIG_BACKLIGHT_CLASS_DEVICE)
 /**
  * drm_panel_of_backlight - use backlight device node for backlight
  * @panel: DRM panel
-- 
2.20.1