ASoC: amd: vangogh: Allow probing ACP PCI when SOF is disabled

Since commit e89f45ed ("ASoC: amd: vangogh: Add check for acp config
flags in vangogh platform"), the Vangogh ACP PCI driver could not be used
anymore for boards which happen to have a matching entry in acp-config
list.

Commit f18818eb ("ASoC: amd: vangogh: Add condition check for acp
config flag") slightly changed the behaviour to permit loading the
driver if AMD_LEGACY flag is set.  However, for AMD_SOF flag the probing
is still denied, even if SOF support is disabled in kernel
configuration.

While this helps preventing conflicts between SOF and generic ACP
drivers, there are cases where a fallback to the generic non-SOF support
would still be needed or useful, e.g. SOF firmware is not available or
doesn't work properly, SOF driver is broken or doesn't provide full
support for a particular hardware, or simply for testing/debugging the
alternative solution.  A real-life example is Steam Deck OLED, which
works with both drivers.

Prevent returning from probe() when ACP config indicates SOF support for
the current board *and* the Vangogh SOF driver is not enabled in kernel
configuration.
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Reviewed-by: Emil Velikov <emil.velikov@collabora.com>
Link: https://msgid.link/r/20231209203229.878730-3-cristian.ciocaltea@collabora.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/amd/vangogh/pci-acp5x.c

@@ -130,9 +130,13 @@ static int snd_acp5x_probe(struct pci_dev *pci,
 	int ret, i;
 	u32 addr, val;
 
-	/* Return if acp config flag is defined */
+	/*
+	 * Return if ACP config flag is defined, except when board
+	 * supports SOF while it is not being enabled in kernel config.
+	 */
 	flag = snd_amd_acp_find_config(pci);
-	if (flag != FLAG_AMD_LEGACY)
+	if (flag != FLAG_AMD_LEGACY &&
+	    (flag != FLAG_AMD_SOF || IS_ENABLED(CONFIG_SND_SOC_SOF_AMD_VANGOGH)))
 		return -ENODEV;
 
 	irqflags = IRQF_SHARED;