ASoC: cs35l56: Support for factory calibration through ALSA controls

ASoC: cs35l56: Support for factory calibration through ALSA controls

Richard Fitzgerald <rf@opensource.cirrus.com> says:

Factory calibration is normally done through debugfs files.
Google have requested that factory calibration can be performed by
repair shops. These repair shops only have access to the standard
"user" kernel, which does not include debugfs.

Patch #1 adds a new control definition macro to create a boolean control
         with specified access permissions. (new in V2)

Patch #2 is the implementation in the cs35l56 driver.