dt-bindings: display: vc4: hdmi: Add BCM2711 HDMI controllers bindings

The HDMI controllers found in the BCM2711 SoC need some adjustments to the
bindings, especially since the registers have been shuffled around in more
register ranges.

Cc: Rob Herring <robh+dt@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Maxime Ripard <maxime@cerno.tech>