media: mediatek: vcodec: Fix v4l2-compliance fail

Need to use default pic info when get pic info fail.

Signed-off-by: Yunfei Dong <yunfei.dong@mediatek.com>
Reviewed-by: Steve Cho <stevecho@chromium.org>
Tested-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>