ASoC: fsl_esai: Remove unneeded definition

There is no need for defining FSL_ESAI_RATES locally as the standard
SNDRV_PCM_RATE_8000_192000 definition can be used instead.

Signed-off-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Mark Brown <broonie@kernel.org>