This patch adds support for resolution change event to notify clients so
they can prepare correct output buffer. When resolution change happened,
G_FMT for CAPTURE should return old resolution and format before CAPTURE
queues streamoff.

This event is used in the Chromium browser project by the V4L2 JPEG
Decode Accelerator (V4L2JDA) to allocate output buffer.
Signed-off-by: Henry-Ruey Hsu <henryhsu@chromium.org>
Signed-off-by: Thierry Escande <thierry.escande@collabora.com>
Acked-by: Andrzej Pietrasiewicz <andrzej.p@samsung.com>
Acked-by: Jacek Anaszewski <jacek.anaszewski@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>