clk: mediatek: mt8188-vdo1: Add VDO1_DPI1_HDMI clock for hdmitx

Add a missing clock found in the VDO1 controller for the HDMI TX
controller over DPI1.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Link: https://lore.kernel.org/r/20250212100342.33618-2-angelogioacchino.delregno@collabora.com


Signed-off-by: Stephen Boyd <sboyd@kernel.org>