dt-bindings: display: rockchip: Add schema for RK3588 HDMI TX Controller

dt-bindings: display: rockchip: Add schema for RK3588 HDMI TX Controller

Rockchip RK3588 SoC integrates the Synopsys DesignWare HDMI 2.1
Quad-Pixel (QP) TX controller IP.

Since this is a new IP block, quite different from those used in the
previous generations of Rockchip SoCs, add a dedicated binding file.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Cristian Ciocaltea <cristian.ciocaltea@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20241016-b4-rk3588-bridge-upstream-v10-2-87ef92a6d14e@collabora.com
Signed-off-by: Maxime Ripard <mripard@kernel.org>