media: vimc: stream: init/terminate the first entity
The s_stream callback was not being called for the first entity in the
stream pipeline array.
Instead of verifying the type of the node (video or subdevice) and
calling s_stream from the second entity in the pipeline, do this process
for all the entities in the pipeline for consistency.
The previous code was not a problem because the first entity is a video
device and not a subdevice, but this patch prepares vimc to allow
setting some configuration in the entity before calling s_stream.