dt-bindings: phy: add binding for the i.MX8MP HDMI PHY

Add a DT binding for the HDMI PHY found on the i.MX8MP SoC.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Adam Ford <aford173@gmail.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Reviewed-by: Luca Ceresoli <luca.ceresoli@bootlin.com>
Tested-by: Tommaso Merciai <tomm.merciai@gmail.com>
Link: https://lore.kernel.org/r/20240227220444.77566-2-aford173@gmail.com


Signed-off-by: Vinod Koul <vkoul@kernel.org>