dt-bindings: display: rockchip: Add rk3576 hdmi controller

RK3576 HDMI TX Controller is very similar to that of RK3588, but
with some control bits for IO and interrupts status scattered across
different GRF.

Signed-off-by: Andy Yan <andy.yan@rock-chips.com>
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20241231094425.253398-3-andyshrk@163.com