[PATCH v5 06/17] ASoC: fsl_ssi: Clear FIFO directly in fsl_ssi_config()

The FIFO clear helper function is just one line of code now. So it could be cleaned up by removing it and calling regmap directly. Meanwhile, FIFO clear could be applied to all use cases, not confined to AC97. So this patch also moves FIFO clear in the trigger() to fsl_ssi_config() and removes

[PATCH v5 06/17] ASoC: fsl_ssi: Clear FIFO directly in fsl_ssi_config()

The FIFO clear helper function is just one line of code now. So it could be cleaned up by removing it and calling regmap directly. Meanwhile, FIFO clear could be applied to all use cases, not confined to AC97. So this patch also moves FIFO clear in the trigger() to fsl_ssi_config() and removes