media: mtk-vcodec: venc: remove redundant code

vidioc_try_fmt() does clamp height and width when called on the OUTPUT
queue, so clamping them prior to calling this function is redundant. Set
the queue's parameters after calling vidioc_try_fmt() so we can use the
values it computed.

Signed-off-by: Alexandre Courbot <acourbot@chromium.org>
Signed-off-by: Irui Wang <irui.wang@mediatek.com>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>