[media] coda: add selection API support for h.264 decoder

The h.264 decoder produces capture frames that are a multiple of the macroblock
size (16 pixels). To inform userspace about invalid pixel data at the edges,
use the active and padded composing rectangles on the capture queue.
The cropping information is obtained from the h.264 sequence parameter set.

Reviewed-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Kamil Debski <k.debski@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>