media: allegro: encode bit fields separately

Even bits in bitfields do not keep their position, but move around or
move to other bitfields. Therefore, the driver has to handle bitfields
differently depending on the firmware version.

Create separate fields for the options that have been in bitfields and
handle the bitfields when encoding the message.

As a side effect, this makes the messages a bit more readable.

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>