ASoC: Intel: sof_cs42l42: use helper function to get bclk frequency

Use sof_dai_get_bclk() function to get bclk frequency instead of a
hard-coded magic number depending on configuration in topology.

Signed-off-by: Brent Lu <brent.lu@intel.com>

sound/soc/intel/boards/sof_cs42l42.c

@@ -16,6 +16,7 @@
 #include <sound/pcm.h>
 #include <sound/pcm_params.h>
 #include <sound/soc.h>
+#include <sound/sof.h>
 #include <sound/soc-acpi.h>
 #include <dt-bindings/sound/cs42l42.h>
 #include "../../codecs/hdac_hdmi.h"
@@ -122,7 +123,12 @@ static int sof_cs42l42_hw_params(struct snd_pcm_substream *substream,
 	struct snd_soc_dai *codec_dai = asoc_rtd_to_codec(rtd, 0);
 	int clk_freq, ret;
 
-	clk_freq = 3072000; /* BCLK freq */
+	clk_freq = sof_dai_get_bclk(rtd); /* BCLK freq */
+
+	if (clk_freq <= 0) {
+		dev_err(rtd->dev, "get bclk freq failed: %d\n", clk_freq);
+		return -EINVAL;
+	}
 
 	/* Configure sysclk for codec */
 	ret = snd_soc_dai_set_sysclk(codec_dai, 0,