Drivers: DAI: Intel: DMIC: Shorten unmute ramp time

This change produces more quickly in the stream valid
audio samples. The start fade-in ramp can be shortened to
100 ms for 48 kHz and 200 ms for 16 kHz. It was before 200 ms
and 400 ms. The updated DMIC hardware in allows to do this
change.

Signed-off-by: Seppo Ingalsuo <seppo.ingalsuo@intel.com>