[PATCH v2 -next] drm/rockchip: cdn-dp-core: fix function not used when PM_SLEEP is not set

[Randy Dunlap]

Fix build warning when CONFIG_PM_SLEEP is not enabled.

../drivers/gpu/drm/rockchip/cdn-dp-core.c:1124:12: warning: ‘cdn_dp_resume’ defined but not used [-Wunused-function]
 static int cdn_dp_resume(struct device *dev)

Fixes: 7c49abb4c2f8 ("drm/rockchip: cdn-dp-core: Make cdn_dp_core_suspend/resume static")
Signed-off-by: Randy Dunlap <rdunlap at infradead.org>
Cc: Sandy Huang <hjc at rock-chips.com>
Cc: Heiko Stübner <heiko at sntech.de>
Cc: dri-devel at lists.freedesktop.org
Cc: David Airlie <airlied at linux.ie>
Cc: Daniel Vetter <daniel at ffwll.ch>
---
v2: use preferred __maybe_unused instead of ifdeffery:
      https://lore.kernel.org/patchwork/patch/732981/

 drivers/gpu/drm/rockchip/cdn-dp-core.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20201214.orig/drivers/gpu/drm/rockchip/cdn-dp-core.c
+++ linux-next-20201214/drivers/gpu/drm/rockchip/cdn-dp-core.c
@@ -1121,7 +1121,7 @@ static int cdn_dp_suspend(struct device
 	return ret;
 }
 
-static int cdn_dp_resume(struct device *dev)
+static __maybe_unused int cdn_dp_resume(struct device *dev)
 {
 	struct cdn_dp_device *dp = dev_get_drvdata(dev);