arm64: dts: qcom: Add initial Milos dtsi

Add a devicetree description for the Milos SoC, which is for example
Snapdragon 7s Gen 3 (SM7635).

Signed-off-by: Luca Weiss <luca.weiss@fairphone.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20251210-sm7635-fp6-initial-v4-8-b05fddd8b45c@fairphone.com


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