amfcodec: add support of AMF AV1 encoder
This draft adds support of AMD AV1 hardware encoder for amfcodec
plugin.
The latest release of AMF SDK added support of AV1 encoder, link. Documentation for AMF AV1 encoder is located here.
The code of this merge request is based on Gstreamer implementation of AMF h265 encoder gstamfh265enc.cpp
Please note that AMF AV1 encoder is only supported by the latest AMD Radeon RX 7900 XTX / XT cards.