ASoC: Intel: bytcr_rt5640: simplify MCLK quirk tests

remove redundant tests to check MCLK (align with other
machine drivers). some checks remain since when the MCLK is
disabled we fall back to using the bclk as PLL reference

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Acked-By: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>