media: mediatek: vcodec: Change encoder v4l2 capability value

Change the value of v4l2 capability parameters: driver and card.

Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>