snd_bcm2835: disable HDMI audio when vc4 is used (#3640)

raspberrypi inclusion
category: feature
bugzilla: 50432

--------------------------------

Things don't work too well when both the vc4 driver and the firmware
driver are trying to control the same audio output:

[  763.569406] bcm2835_audio bcm2835_audio: vchi message timeout, msg=5

Hence, when the vc4 HDMI driver is used, let it control audio. This is done
by introducing a new device tree property to the audio node, and
extending the vc4-kms-v3d overlays to set it appropriately.
Signed-off-by: NHristo Venev <hristo@venev.name>
Signed-off-by: NFang Yafen <yafen@iscas.ac.cn>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

drivers/staging/vc04_services/bcm2835-audio/bcm2835.c

@@ -381,7 +381,9 @@ static int snd_bcm2835_alsa_probe(struct platform_device *pdev)
 	}
 
 	if (!enable_compat_alsa) {
+		if (!of_property_read_bool(dev->of_node, "brcm,disable-hdmi"))
 			set_hdmi_enables(dev);
+
 		// In this mode, always enable analog output
 		enable_headphones = true;
 	} else {