media: staging: tegra-vde: Mark tegra_vde_runtime_suspend/resume as __maybe_unused

If CONFIG_PM is not set, gcc warns:

drivers/staging/media/tegra-vde/vde.c:916:12:
 warning: 'tegra_vde_runtime_suspend' defined but not used [-Wunused-function]

Make it __maybe_unused to fix this.
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Reviewed-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>

drivers/staging/media/tegra-vde/vde.c

@@ -913,7 +913,7 @@ static irqreturn_t tegra_vde_isr(int irq, void *data)
 	return IRQ_HANDLED;
 }
 
-static int tegra_vde_runtime_suspend(struct device *dev)
+static __maybe_unused int tegra_vde_runtime_suspend(struct device *dev)
 {
 	struct tegra_vde *vde = dev_get_drvdata(dev);
 	int err;
@@ -929,7 +929,7 @@ static int tegra_vde_runtime_suspend(struct device *dev)
 	return 0;
 }
 
-static int tegra_vde_runtime_resume(struct device *dev)
+static __maybe_unused int tegra_vde_runtime_resume(struct device *dev)
 {
 	struct tegra_vde *vde = dev_get_drvdata(dev);
 	int err;