hal: Reduce offload latency and log spam

Offload latency is set to 96. Change
it to 50 to reflect the rendering latency more correctly
Modify pcm offload latency to return offload
latency rather than the latency based on buffering
since volume is applied immediately for offload use
cases. Also reduce log spam in offload use cases

Change-Id: If28d49d66e8f989074c4c7eaec523855e9f4290a
CRs-Fixed: 787448