ASoC: cs35l56: Set access permissions on volatile

Merge series from Richard Fitzgerald <rf@opensource.cirrus.com>:

The CAL_SET_STATUS and CAL_DATA_RB controls are volatile and read-only, but
the existing ASoC macros to define controls don't allow setting access
permissions, so those controls were marked as non-volatile read/write.
These four patches fix that.

The first two patches add two new control macros to soc.h. I really don't
like codec drivers open-coding a kcontrol_new content for a control that
will be managed by the ASoC info/get/put handlers. If a new type of ASoC
control definition is needed it's better to have it in soc.h so all the
dependencies between ASoC and the kcontrol_new content are in one place.