ASoC: Intel: byt-rt5640: Use init time DAI format

Setting static DAI format has been supported in the soc-core quite some time
now so there is no need to set it runtime in machine driver.

Signed-off-by: Jarkko Nikula <jarkko.nikula@linux.intel.com>
Acked-by: Liam Girdwoood <liam.r.girdwood@linux.intel.com>
Signed-off-by: Mark Brown <broonie@linaro.org>