ASoC: Intel: avs: Add rt5640 board support

Merge series from Cezary Rojewski <cezary.rojewski@intel.com>:

Small set of patches intoducing two low-impact improvements to rt5640
codec driver and then avs_rt5640 machine board driver. The board
behavior is based on existing boards such as avs_rt274.

In regard to the retry-device-verification change, there is number of
similar "fixes" found in the Realtek code in sound/soc/codecs. What I
provide here is verified with tests, the delay is not mentioned in the
spec I have access to.