[media] vb2: Add support for non monotonic timestamps

[media] vb2: Add support for non monotonic timestamps

Not all drivers use monotonic timestamps. This patch adds a way to set the
timestamp type per every queue.
In addition, set proper timestamp type in drivers that I am sure that use
either MONOTONIC or COPY timestamps. Other drivers will correctly report
UNKNOWN timestamp type instead of assuming that all drivers use monotonic
timestamps.

Signed-off-by: Kamil Debski <[email protected]>
Signed-off-by: Kyungmin Park <[email protected]>
Reviewed-by: Sylwester Nawrocki <[email protected]>
Acked-by: Hans Verkuil <[email protected]>
Signed-off-by: Sylwester Nawrocki <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>