ASoC: imx-card: improve the sound quality for low rate

ASoC: imx-card: improve the sound quality for low rate

According to RM, on auto mode:
For codec AK4458 and AK4497, the lowest ratio of MLCK/FS is 256
if sample rate is 8kHz-48kHz,
For codec AK5558, the lowest ratio of MLCK/FS is 512 if sample
rate is 8kHz-48kHz.

With these setting the sound quality for 8kHz-48kHz can be improved.

Fixes: 32569b1134f1 ("ASoC: imx-card: Add imx-card machine driver")
Signed-off-by: Shengjiu Wang <shengjiu.wang@nxp.com>
Link: https://lore.kernel.org/r/1641292835-19085-4-git-send-email-shengjiu.wang@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>