media: venus: Enable h.264 hierarchical coding

HFI supports hierarchical P encoding and the ability to specify the
bitrate for the different layers.

Connect the controls that V4L2 provides and HFI supports.

Signed-off-by: Fritz Koenig <frkoenig@chromium.org>
Reviewed-by: Dikshita Agarwal <quic_dikshita@quicinc.com>
Signed-off-by: Stanimir Varbanov <stanimir.k.varbanov@gmail.com>
Signed-off-by: Hans Verkuil <hverkuil@xs4all.nl>