nuplayer: Fixes for PCM offload

 * Bring us more in line with upstream.
 * This code modifies NuPlayer to be less error-driven when
   invoking PCM offload.
 * Small bufs feature is currently disabled in this patch, as
   the 8974 DSP does not handle it correctly.

Change-Id: I35ce0d9e55baf0c871d03a5456b47309c34350d4