mtk-jpegenc: add jpeg encode worker interface

Add jpeg encoding worker to ensure that two HWs
run in parallel in MT8195.

Signed-off-by: kyrie wu <kyrie.wu@mediatek.com>
Signed-off-by: irui wang <irui.wang@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>