ASoC: codecs: wcd93xxx: remove code duplication

ASoC: codecs: wcd93xxx: remove code duplication

Merge series from Srinivas Kandagatla <srinivas.kandagatla@oss.qualcomm.com>:

All the Qualcomm WCD codecs and WCD based codecs have lots of code in
common, resulting in lot of duplicate code.
This series is an attempt to clean some of this by moving the common
code to wcd-common library or to soundwire helper functions.

Currently I have done cleanups for 4 codecs wcd934x, wcd937x, wcd938x
and wcd939x, however any new Qualcomm codecs can avoid this duplication
by using the wcd-common library.

I have also added two helpers of_sdw_find_device_by_node() and
sdw_slave_get_current_bank() in soundwire layer for the codecs to use them,
this series was already acked by Soundwire maintainer Vinod.

As original cleanup series was depending on the new soundwire interfaces
I have combined both the series as they are cleaning up code
duplications.

As am touching the same codec drivers, 2 bug fixes are also added at the
start of the series.

There is still lot of code that is duplicate, but this is just a
starting point for such cleanups.

I have tested this on T14s, any testing is appreciated.