media: amphion: decoder implement display delay enable

amphion vpu support a low latency mode,
when V4L2_CID_MPEG_VIDEO_DEC_DISPLAY_DELAY_ENABLE is enabled,
decoder can display frame immediately after it's decoded.
Only h264 is support yet.

Fixes: 6de8d628 ("media: amphion: add v4l2 m2m vpu decoder stateful driver")
Signed-off-by: Ming Qian <ming.qian@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>