ASoC: SOF: get pipeline instance id from pipe_widget->instance_id

Merge series from Bard Liao <yung-chuan.liao@linux.intel.com>:

Currently we set pipeline instance id = swidget->pipeline_id, but
pipeline_id is from topology and can be any number. In fact, the
number of pipelines is limited. This patch use ida to allocate pipeline
instance id and will be used for pipeline instance id in the IPC
message.