arm64: dts: qcom: sc7280: Add gpu support

Add the necessary dt nodes for gpu support in sc7280.

Signed-off-by: Akhil P Oommen <akhilpo@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/1628691835-36958-1-git-send-email-akhilpo@codeaurora.org