arm64: dts: qcom: msm8998: Add DPU1 nodes

Add the required nodes to support the display hardware on msm8998.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
[konrad: update the commit msg and AGdR's email, rebase]
Signed-off-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Link: https://lore.kernel.org/r/20230805-topic-8998_dpu-v1-1-9d402dc1ecc0@linaro.org


Signed-off-by: Bjorn Andersson <andersson@kernel.org>