arm64: dts: qcom: msm8998: Configure Adreno GPU and related IOMMU

The MSM8998 SoC includes an Adreno 540.1 GPU, with a maximum frequency
of 710MHz. This GPU may or may not accept a ZAP shader, depending on
platform configuration, so adding a zap-shader node is left to the
board DT.

Signed-off-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@somainline.org>
Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Link: https://lore.kernel.org/r/20210901183123.1087392-5-angelogioacchino.delregno@somainline.org