ASoC: fsl_sai: Fix pins setting for i.MX8QM platform

SAI on i.MX8QM platform supports the data lines up to 4. So the pins
setting should be corrected to 4.

Fixes: eba0f007

 ("ASoC: fsl_sai: Enable combine mode soft")
Signed-off-by: Chancel Liu <chancel.liu@nxp.com>
Acked-by: Shengjiu Wang <shengjiu.wang@gmail.com>
Reviewed-by: Iuliana Prodan <iuliana.prodan@nxp.com>
Link: https://lore.kernel.org/r/20230418094259.4150771-1-chancel.liu@nxp.com
Signed-off-by: Mark Brown <broonie@kernel.org>