arm64: dts: mediatek: mt8183-pumpkin: add HDMI support

arm64: dts: mediatek: mt8183-pumpkin: add HDMI support

The MT8183 Pumpkin board has a micro-HDMI connector. HDMI support is
provided by an IT66121 DPI <-> HDMI bridge.

Enable the DPI and add the node for the IT66121 bridge.

Signed-off-by: Fabien Parent <fparent@baylibre.com>
Co-developed-by: Pin-yen Lin <treapking@chromium.org>
Signed-off-by: Pin-yen Lin <treapking@chromium.org>
Reviewed-by: Nícolas F. R. A. Prado <nfraprado@collabora.com>
Link: https://lore.kernel.org/r/20240919094212.1902073-1-treapking@chromium.org
Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>