hal: allow to get render position for non-offload use cases

For pcm voip use case which goes with direct output, render
position can be queried from HAL, while currently it is not
supported and always return with invalid status.

Return with written frames for pcm use cases when render
position queried from HAL.

CRs-Fixed: 828864

Change-Id: I5fec7f5fc1f61dc36cbeb41a4121c2c83f63b7f4