dt-bindings: display/msm: sdm845-dpu: Describe SDM670

The SDM670 display controller has the same requirements as the SDM845
display controller, despite having distinct properties as described in
the catalog. Add the compatible for SDM670 to the SDM845 controller.

Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Richard Acayan <mailingradian@gmail.com>
Patchwork: https://patchwork.freedesktop.org/patch/562959/
Link: https://lore.kernel.org/r/20231017021805.1083350-11-mailingradian@gmail.com


Signed-off-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>