arm64: dts: qcom: add sm8150 hdk dts

Add initial HDK855 dts, based on sm8150-mtp, with a few changes.

Signed-off-by: Jonathan Marek <jonathan@marek.ca>
Link: https://lore.kernel.org/r/20200609194030.17756-8-jonathan@marek.ca


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