ASoC: fsl_ssi: Setup AC97 in fsl_ssi_hw_init()

AC97 configures most of registers earlier to start a communication
with CODECs in order to successfully initialize CODEC. Currently,
_fsl_ssi_set_dai_fmt() and fsl_ssi_setup_ac97() are called to get
all SSI registers properly set.

Since now the driver has a fsl_ssi_hw_init() to handle all register
initial settings, this patch moves those register settings of AC97
to the fsl_ssi_hw_init() as well.

Meanwhile it applies _fsl_ssi_set_dai_fmt() call to AC97 only since
other formats would be configured via normal set_dai_fmt() directly.

This patch also adds fsl_ssi_hw_clean() to cleanup control bits for
AC97 in the platform remote() function.

Signed-off-by: Nicolin Chen <nicoleotsuka@gmail.com>
Tested-by: Caleb Crome <caleb@crome.org>
Tested-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Reviewed-by: Maciej S. Szmigiero <mail@maciej.szmigiero.name>
Signed-off-by: Mark Brown <broonie@kernel.org>