ASoC: Intel: bytcr-rt5640: add Asus T100TAF quirks

Add quirk based on DMI string matching
Also fix matching to use DMI_EXACT_MATCH otherwise T100TA and T100TAF
will be using same quirk

Signed-off-by: Pierre-Louis Bossart <pierre-louis.bossart@linux.intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>