media: platform: Add jpeg enc feature

Add mtk jpeg encode v4l2 driver based on jpeg decode, because that jpeg
decode and encode have great similarities with function operation.

Reviewed-by: Tomasz Figa <tfiga@chromium.org>
Signed-off-by: Xia Jiang <xia.jiang@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>