ASoC: Improve SDCA support for duplicated features

ASoC: Improve SDCA support for duplicated features

Charles Keepax <ckeepax@opensource.cirrus.com> says:

There are some short comings of the current SDCA class driver with
respect to duplicated functions and jacks. Fix some issues in the
reporting of jacks when there are multiple jacks represented in the SDCA
topology. When a single device contains multiple instances of the same
type of SDCA function the current class driver will create duplicate
controls, update the code to fix this. Finally whilst working through
this also tidy up the handling of the sdca_function_desc pointers as it
turns out some duplication has crept into the code on that front.