Fix processing of etl gpu packets
Fix processing of etl gpu packets

Previously I interpreted incorrectly the meaning of the QueuePacket
event.

The mapping that we actually want is:
  * QueuePacket/Info -> Received by SW scheduler
  * DmaPacket/Start -> Moved to the HW queue
  * DmaPacket/Info -> Finished processing by gpu ISR

Verified by comparing against gpuview output.

mikesart/gpuvis,mikesart/gpuvis,mikesart/gpuvis