arm64: dts: qcom: sc7280: Add basic dts/dtsi files for sc7280 soc

Add initial device tree support for the sc7280 SoC and the IDP
boards based on this SoC

Signed-off-by: Rajendra Nayak <rnayak@codeaurora.org>
Reviewed-by: Stephen Boyd <swboyd@chromium.org>
Link: https://lore.kernel.org/r/1615461961-17716-4-git-send-email-rnayak@codeaurora.org


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