media: amphion: add v4l2 m2m vpu encoder stateful driver

This consists of video encoder implementation plus encoder controls.

Signed-off-by: Ming Qian <ming.qian@nxp.com>
Signed-off-by: Shijie Qin <shijie.qin@nxp.com>
Signed-off-by: Zhou Peng <eagle.zhou@nxp.com>
Tested-by: Nicolas Dufresne <nicolas.dufresne@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>