media: camss: csid: Different format support on source pad

Usually the format on the source pad is the same as on the sink pad.
However the CSID is able to do some format conversions. To support
this make the format on the source pad selectable amongst a list
of formats. This list can be different for each sink pad format.
This is still not used but will be when the format conversions
are implemented.

Signed-off-by: Todor Tomov <todor.tomov@linaro.org>
Signed-off-by: Hans Verkuil <hansverk@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>