Dynamic routing for compressed streams.

Changes for V2

* We no longer copy the compressed params into the BE hw_params. This
was bogus, but didn't show up on Haswell testing as the BE params were never used. The DSP ran the BE is a fixed configuration so all BE params were ignored.

* The BE hw_params are now zeroed to force the machine driver to fixup
the BE configuration. i.e. machine driver can query the DSP encodec/decoder for correct hw_params given the use case.

* No longer need to allocate memory for hw_params.

Regards

Liam

Applied both, thanks.