Enable S/PDIF controller to enable HDMI audio support on Toshiba AC100.
Use nvidia,fixed-parent-rate property that prevents audio rate conflict
between S/PDIF and I2S.
Tested-by: Agneli <poczt@protonmail.ch>
Signed-off-by: Dmitry Osipenko <digetx@gmail.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>