st-hal: Update custom config data for merged sound model usecases

There is a usecase in which one of the merged client sessions does
not have custom config data and another one does. In this usecase,
the hardware config custom data needs to be updated so that the
custom config param can be sent to DSP.

Change-Id: I296f6db2ad3394e35237c54a488697a985b73c1f
1 file changed