media: allegro: support handling firmware dependent values

Like the message format, also the identifiers in the messages differ
between firmware versions. This especially affects the identifier for
the codec that shall be used. As the messages used by the driver are now
independent from the firmware, we can use the values defined by V4L2 as
identifiers in the messages.

Convert the V4L2 codec format to the respective firmware value when
encoding the messages to binary format instead beforehand.

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>