hal: Offload bugfixes

 * Always reset the bit width and sample rate if any active offload
   stream is different. Failure to do this can crash the DSP, and
   certain limitations come into play when a high samplerate is used
   such as effects being unavailable.
 * Don't send errors to the framework when the timestamp query fails
   before the stream is up and running.

Change-Id: Ieeaafe8965e3cdc69b8dd64be85fbb3bf48c020b