arm64: dts: mediatek: mt8195: Assign dp-intf aliases

Assign aliases for the primary and secondary dp-intf IP to properly
and reliably enable DisplayPort functionality.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Tested-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Chen-Yu Tsai <wenst@chromium.org>
Reviewed-by: Alexandre Mergnat <amergnat@baylibre.com>
Link: https://lore.kernel.org/r/20230424112523.1436926-3-angelogioacchino.delregno@collabora.com


Signed-off-by: Matthias Brugger <matthias.bgg@gmail.com>