ASoC: fsl_sai: add 12kHz, 24kHz, 176.4kHz and 192kHz sample rate support

Normally we don't support 12kHz, 24kHz in audio driver, alsa didn't
have formal definition of 12kHz, 24kHz, but alsa supply a way to
support these sample rates. And add 176.4kHz and 192kHz support.

Signed-off-by: Zidan Wang <zidan.wang@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>