ASoC: atmel: mchp-pdmc: set prepare_slave_config

Since a pointer to struct snd_dmaengine_pcm_config is passed,
snd_dmaengine_pcm_prepare_slave_config() is no longer called unless it's
explicitly set in prepare_slave_config.

Fixes: 50291652 ("ASoC: atmel: mchp-pdmc: add PDMC driver")
Suggested-by: Sascha Hauer <sha@pengutronix.de>
Signed-off-by: Codrin Ciubotariu <codrin.ciubotariu@microchip.com>
Link: https://lore.kernel.org/r/20220421125403.2180824-2-codrin.ciubotariu@microchip.comSigned-off-by: Mark Brown <broonie@kernel.org>

sound/soc/atmel/mchp-pdmc.c

@@ -966,6 +966,7 @@ static int mchp_pdmc_process(struct snd_pcm_substream *substream,
 
 static struct snd_dmaengine_pcm_config mchp_pdmc_config = {
 	.process = mchp_pdmc_process,
+	.prepare_slave_config = snd_dmaengine_pcm_prepare_slave_config,
 };
 
 static int mchp_pdmc_probe(struct platform_device *pdev)