This is an (at least somewhat complete) logical emulator of the a6xx SQE
that lets us step through firmware execution (bootstrap, cmdstream pkt
handling, etc).  It lets us poke at various fw visible state and run
through pm4 packet(s) to better understand what the fw is doing when it
handles various packets.

Signed-off-by: Rob Clark <robdclark@chromium.org>
Part-of: <!10944>