media: allegro: pass buffers through firmware

As we know which buffers are processed by the codec from the address in
the ENCODE_FRAME response, we can queue multiple buffers in the firmware
and retrieve the buffer from the response of the firmware. This enables
the firmware to use the internal scheduling the codec and avoids round
trips through the driver when fetching the next frame.

Remove buffers that have been passed to the firmware from the m2m buffer
queue and put them into a shadow queue for tracking the buffer in the
driver. When we receive a ENCODE_FRAME response from the firmware, get
the buffer from the shadow queue and finish the buffer.

Furthermore, it is necessary to finish the job straight after passing
the buffer to the firmware to allow the V4L2 framework to send further
buffers to the driver.

Signed-off-by: Michael Tretter <m.tretter@pengutronix.de>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>