drm/vc4: hdmi: Depends on CONFIG_PM

We already depend on runtime PM to get the power domains and clocks for
most of the devices supported by the vc4 driver, so let's just select it
to make sure it's there.

Link: https://lore.kernel.org/r/20220629123510.1915022-38-maxime@cerno.techAcked-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Stefan Wahren <stefan.wahren@i2se.com>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
(cherry picked from commit f1bc386b)
Signed-off-by: Maxime Ripard <maxime@cerno.tech>

drivers/gpu/drm/vc4/Kconfig

@@ -8,6 +8,7 @@ config DRM_VC4
 	depends on DRM
 	depends on SND && SND_SOC
 	depends on COMMON_CLK
+	depends on PM
 	select DRM_DISPLAY_HDMI_HELPER
 	select DRM_DISPLAY_HELPER
 	select DRM_KMS_HELPER

drivers/gpu/drm/vc4/vc4_hdmi.c

@@ -2855,7 +2855,7 @@ static int vc5_hdmi_init_resources(struct vc4_hdmi *vc4_hdmi)
 	return 0;
 }
 
-static int __maybe_unused vc4_hdmi_runtime_suspend(struct device *dev)
+static int vc4_hdmi_runtime_suspend(struct device *dev)
 {
 	struct vc4_hdmi *vc4_hdmi = dev_get_drvdata(dev);